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Morphometric variations of two patellid limpets between artificial breakwaters and natural reefs

Abstract

Artificial shorelines often differ from natural reefs in shape, composition, and habitat complexity. They promote higher accumulation of pollutants and increased physiological stress, which lead to changes in species distributions and ecosystem functioning. This can promote trophic shifts and reduced genetic diversity of gastropod populations inhabiting artificial shorelines and might promote morphological changes, which may influence behaviour, vulnerability to predation, feeding efficiency, sex ratios, reproductive development, and overall fitness. This study explores inter- and intraspecific shell morphometric variations in Patella rustica and P. caerulea between breakwaters (ripraps) and natural reefs in three sites of Ceuta (North Africa, Spain), including a physicochemical assessment of the studied locations: shore orientation, inclination and wave exposure, and substratum nature, heterogeneity and roughness. Limpets on artificial substrata had a slightly smaller extra-visceral cavity and flattened shell profile, which suggests that the desiccation and temperature stress driven by the lithological composition and roughness of the studied substrata might have influenced the registered shell shape variation. However, the high morphometric variation registered for both species across sites and substrata suggests that limpets' morphology might be responding to a complex interaction of environmental and ecological factors rather than solely rock type. The findings of this study highlight the complex interplay between rock type and local environmental conditions in shaping patellid limpets’ shell morphology and provide insights into the adaptive mechanisms that drive shell shape variation in limpet populations in the face of coastal sprawl and anthropogenic global change.

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Morphometric variations of two patellid limpets between artificial breakwaters and natural reefs

Author: Sempere Valverde, Juan; Ostalé Valriberas, Enrique; Espinosa Torre, Free; Márquez, Federico
Publisher: Elsevier
Year: 2024
DOI: 10.1016/j.ecss.2024.108617
Source: https://idus.us.es/bitstreams/93f66b0c-1123-4666-af9c-d9be9305861f/download
Es ua ine, Coas al and Shel Science 297 (2024) 108617
A ailable online 4 Janua y 2024
0272-7714/© 2024 The Au ho s. Published by Else ie L d. This is an open access a icle unde he CC BY license (h p://c ea i ecommons.o g/licenses/by/4.0/).
Mo phome ic a ia ions o wo pa ellid limpe s be ween a i icial
b eakwa e s and na u al ee s
Juan Sempe e-Val e de
a
,
*
, En ique Os al´
e-Val ibe as
a
, F ee Espinosa
a
, Fede ico M´
a quez
b
,
c
a
Labo a o io de Biología Ma ina/Es aci´
on de Biología Ma ina Del Es echo (Ceu a), Depa amen o de Zoología, Facul ad de Biología, Uni e sidad de Se illa, A da.
Reina Me cedes s/n, 41012, Se illa, Spain
b
Ins i u o de Biología de O ganismos Ma inos (IBIOMAR) - CONICET, Boule a d B own 2915, U9120ACF, Pue o Mad yn, Chubu , A gen ina
c
Uni e sidad Nacional de La Pa agonia San Juan Bosco, Boule a d B own 3051, U9120ACD, Pue o Mad yn, Chubu , A gen ina
ARTICLE INFO
Keywo ds:
Gas opoda
Pa ellidae
Geome ic mo phome ics
Coas al u baniza ion
In e idal
ABSTRACT
A i icial sho elines o en di e om na u al ee s in shape, composi ion, and habi a complexi y. They p omo e
highe accumula ion o pollu an s and inc eased physiological s ess, which lead o changes in species dis i-
bu ions and ecosys em unc ioning. This can p omo e ophic shi s and educed gene ic di e si y o gas opod
popula ions inhabi ing a i icial sho elines and migh p omo e mo phological changes, which may in luence
beha iou , ulne abili y o p eda ion, eeding e iciency, sex a ios, ep oduc i e de elopmen , and o e all
i ness. This s udy explo es in e - and in aspeci ic shell mo phome ic a ia ions in Pa ella us ica and P. cae ulea
be ween b eakwa e s ( ip aps) and na u al ee s in h ee si es o Ceu a (No h A ica, Spain), including a
physicochemical assessmen o he s udied loca ions: sho e o ien a ion, inclina ion and wa e exposu e, and
subs a um na u e, he e ogenei y and oughness. Limpe s on a i icial subs a a had a sligh ly smalle ex a-
isce al ca i y and la ened shell p o ile, which sugges s ha he desicca ion and empe a u e s ess d i en
by he li hological composi ion and oughness o he s udied subs a a migh ha e in luenced he egis e ed shell
shape a ia ion. Howe e , he high mo phome ic a ia ion egis e ed o bo h species ac oss si es and subs a a
sugges s ha limpe s’ mo phology migh be esponding o a complex in e ac ion o en i onmen al and ecological
ac o s a he han solely ock ype. The indings o his s udy highligh he complex in e play be ween ock ype
and local en i onmen al condi ions in shaping pa ellid limpe s’ shell mo phology and p o ide insigh s in o he
adap i e mechanisms ha d i e shell shape a ia ion in limpe popula ions in he ace o coas al sp awl and
an h opogenic global change.
1. In oduc ion
Coas al sp awl has d ama ically al e ed in e idal ecosys ems
wo ldwide, esul ing in changes in species dis ibu ions, communi y
s uc u e and ecosys em unc ioning (Connell and Glasby, 1999; Sei z
e al., 2006; Bishop e al., 2017; Masucci and Reime , 2019). A i icial
s uc u es a e poo su oga es o na u al ecosys ems and o en lack
spa ial he e ogenei y a di e se spa ial scales, causing an o e all
educ ion in habi a complexi y (Moschella e al., 2005; Fi h e al.,
2015; Cacabelos e al., 2018; Os al´
e-Val ibe as e al., 2018). A he
in e idal le el, su ace o ien a ion, inclina ion and he e ogenei y
de e mine he composi ion o he communi y and can de e mine he
a ailabili y o e uge agains desicca ion and empe a u e s ess, as well
as g azing and p eda ion p essu e (Mo ei a e al., 2006; Bulle i and
Chapman, 2010; Aguile a e al., 2019; Ams u z e al., 2021). Mo eo e ,
oughness, along wi h o he subs a um cha ac e is ics, such as colou ,
shape, pH and li hology, could in luence species se lemen and he
physical s ess expe ienced by he communi ies inhabi ing ocky su -
aces (Ri e a-Ing aham e al., 2013; Hanlon e al., 2018; Sempe -
e-Val e de e al., 2023). Fu he mo e, aunal popula ions inhabi ing
a i icial ha d subs a a can show highe accumula ion o hea y me als
and o he pollu an s, highe s ess le els, shi s in he ophic niche and a
educed gene ic di e si y when compa ed o na u al habi a s (Sedano
e al., 2020a, 2020c; Sei z e al., 2006; Espinosa e al., 2021). Due o
hese cons ain s, many local na i e species ha e ouble colonizing
a i icial subs a a, which can lead o al e ed popula ion s uc u e and
educed geno ypic and pheno ypic di e si y o ma ine o ganisms, p o-
mo ing he agmen a ion o na i e species popula ions and con ibu ing
* Co esponding au ho .
E-mail add ess: [email p o ec ed] (J. Sempe e-Val e de).
Con en s lis s a ailable a ScienceDi ec
Es ua ine, Coas al and Shel Science
jou nal homepage: www.else ie .com/loca e/ecss
h ps://doi.o g/10.1016/j.ecss.2024.108617
Recei ed 3 June 2023; Recei ed in e ised o m 26 Decembe 2023; Accep ed 3 Janua y 2024
Es ua ine, Coas al and Shel Science 297 (2024) 108617
2
o he loss o coas al biodi e si y (Fau elo e al., 2009, 2012; Fi h
e al., 2013, 2016; Bishop e al., 2017; Al e e al., 2020).
Limpe s a e common inhabi an s o in e idal habi a s and play
impo an ecological oles in ocky in e idal communi ies as p ima y
consume s and ecosys em enginee s, in luencing ecosys em dynamics
(Bu gos-Rubio e al., 2015). Due o hei ecological impo ance and
abili y o espond o changes in habi a s uc u e, limpe s ha e been
widely s udied in he con ex o coas al u baniza ion and a i icial
subs a a (e.g., Espinosa e al., 2009, 2011, 2021; Fau elo e al., 2009;
Chapman and Unde wood, 2011). Al hough coas al s uc u es always
ha e a nega i e ecological impac because hey eplace na u al habi a s,
he in oduc ion o seawalls, b eakwa e s and je ies can ha e bo h
posi i e and nega i e e ec s on limpe popula ions (e.g., Mo ei a e al.,
2006; Ri e a-Ing aham e al., 2011a; Bonnici e al., 2013; Cacabelos
e al., 2016). A i icial subs a a p o ide colonizable su aces ha migh
sus ain high densi y o limpe s, leading o inc eased popula ion numbe s
o ce ain limpe species (Ri e a-Ing aham e al., 2011a; Bonnici e al.,
2013; Os al´
e-Val ibe as e al., 2023). Howe e , a i icial sho elines can
also p o ide low-quali y habi a s, lacking e ugia, causing ophic shi s
and a ou ing non-indigenous species, which can nega i ely impac
na i e limpe s ep oduc i e po en ial o he ex en o no being able o
sus ain iable limpe s’ popula ions (Bu gos-Rubio e al., 2015; Sedano
e al., 2020a; Espinosa e al., 2021; B anch e al., 2023; Ea p e al.,
2023). Mo eo e , a i icial subs a a can lead o educed gene ic di-
e si y wi hin limpe s’ popula ions and an inc eased gene ic di e en-
ia ion om popula ions in na u al a eas, which sugges s ha a i icial
habi a s may selec o dis inc and na owe ange o geno ypic ai s
han na u al a eas (Fau elo e al., 2009, 2012). This would ha e
conse a ional implica ions, as hese limpe s could be less esis an o
en i onmen al s esso s and ecological impac s. None heless, his
educed gene ic di e si y and inc eased di e en ia ion could also be due
o a ounde e ec , as he popula ions migh be s ill se ling on he
ecen ly deployed a i icial habi a (Bishop e al., 2017 and e e ences
he ein). In any case, he e ec s o subs a um ype and shape on limpe
popula ions a e complex and con ex -dependen , and u he esea ch is
needed o be e unde s and hese e ec s and o de elop e ec i e
managemen s a egies o conse ing limpe popula ions in u banized
coas al en i onmen s (Lima e al., 2016; Sedano e al., 2020a, 2020b;
Espinosa e al., 2011, 2021; Fau elo e al., 2012; Os al´
e-Val ibe as
e al., 2022).
Gas opod shells a e widely used as indica o s o en i onmen al
changes in ma ine ecosys ems, and limpe s’ shell pa ame e s, such as
heigh , hickness, and leng h, can be nega i ely a ec ed by pollu ion
s ess (Nakhle, 2003; M´
a quez e al., 2011, 2017; Gha ed e al., 2019;
Ha ayashiki e al., 2020; Land o e al., 2021). The e o e, he analysis o
shell shape can p o ide aluable insigh s in o he o e all heal h o
ma ine ecosys ems and he impac o abio ic and bio ic s esso s, such as
u ban p oximi y (Doyle e al., 2022; Mal se a e al., 2022). O e all,
limpe s’ shell shape is de e mined by an in e play o gene ic and en i-
onmen al ac o s (Ba elli, 2016; Nu˜
nez e al., 2018; Nu˜
nez and
Fe n´
andez I ia e, 2022), and limpe s’ shells a e cha ac e ized by high
pheno ypical plas ici y in shape, which has been linked o habi a
adap a ion (Puig, 2016; Bouzaza and Mezali, 2018, 2019; Eche e y
e al., 2020; Vasconcelos e al., 2021; Belmokh a e al., 2022). Fo
example, limpe s in highe idal le els and wa me la i udes end o ha e
a alle shell p o ile, which educes desicca ion and empe a u e s ess
by educing hea ans e om sunligh adia ion and conduc ion wi h
he subs a e (Ve meij, 1973; P usina, 2013). Simila ly, a mo e cen ed
shell apex and ci cula base inc ease adhesion s eng h o he subs a e
and could be an adap a ion o a eas wi h high wa e ac ion (Denny and
Blanche e, 2000; Paulo Cab al, 2007; Bouzaza and Mezali, 2019).
Va ying u baniza ion p essu e can also impac limpe s shell shape
(Gha ed e al., 2019; Land o e al., 2021). Fo example, Tablado and
Gappa (2001) desc ibed bigge panpulmona e limpe s wi h highe shell
p o iles inside a ha bou han nea by habi a s exposed o wa e ac ion. I
was hypo hesized ha he di e ences in size could be due o he
a ailabili y o longe o aging pe iods due o he absence o wa e
dis u bance inside he po . Simila ly, Land o e al. (2021) and Nu˜
nez
e al. (2012) ound his ological al e a ions, shells wi h globula mal-
o ma ions, dec eased shell hickness and ha dness, and a alle shell
p o ile in a eas unde an h opogenic impac . In addi ion, he alle shell
p o iles de ec ed inside ha bou s in hese s udies migh be a esponse o
lowe wa e ac ion o o di e ences in subs a um o ien a ion and o he
en i onmen al pa ame e s o ele ance o limpe s ha could ha e
di e ed be ween he s udied loca ions (Tablado and Gappa, 2001;
Seab a e al., 2011; Nu˜
nez e al., 2012; Land o e al., 2021). Howe e ,
mo e esea ch is needed o unde s and he adap a ion o limpe s o
di e en habi a s and how subs a um ype can in luence limpe s’
mo phology.
Geome ic mo phome ics can p o ide mo e insigh in o complex
shape a ia ion han classical echniques (Zeldi ch e al., 2012). Geo-
me ic mo phome ics uses mul i a ia e me hods o iden i y sub le
shape a ia ions be ween popula ions and species by he analysis o
in ica e de ails, like cu a u e and sculp u e pa e ns, which could help
seg ega e species o unde s and ecological adap a ions (Fa ia e al.,
2017; Ma os e al., 2020; Mame e al., 2021). Using geome ic mo -
phome ics, his s udy aims o explo e mo phome ic a ia ions in
limpe shell shape be ween a i icial and na u al subs a a in di e en
si es o Ceu a (N A ica, Spain) and he possible in luence o a se ies o
physicochemical a iables in he obse ed shell shape pa e ns. To his
end, he ollowing al e na i e hypo heses ha e been es ed. H1: he shell
shape o P. us ica and P. cae ulea a y be ween a i icial b eakwa e s
( ip aps) and na u al ocky ee s; H2: his shell a ia ion has he same
change di ec ion in di e en si es wi hin he a ea o s udy; and H3: he
shell o m (shape +size) a ia ion egis e ed among si es and be ween
subs a a is coinciden wi h di e ences in physicochemical pa ame e s
ela ed o subs a um ype, wa e exposu e and spa ial con igu a ion o
he s udied si es and subs a a.
2. Me hods
2.1. S udy a ea and species selec ion
The S ai o Gib al a is a egion o high biodi e si y and ecological
impo ance due o i s loca ion be ween biogeog aphical egions, making
i key a ea o connec i i y o popula ions ha a e ulne able o impac s,
and a p io i y a ea o conse a ion (Ri e a-Ing aham e al., 2013;
Os al´
e-Val ibe as e al., 2022). Pa ella us ica and P. cae ulea a e wo
common in e idal limpe species ha a e widely dis ibu ed h oughou
he Medi e anean Sea and he NE A lan ic Ocean. In Ceu a (S ai o
Gib al a ), limpe species ha e been ound in g ea e densi ies on a i-
icial han na u al subs a a (see Os al´
e-Val ibe as e al., 2018, 2022).
This is due o a educed human collec ion p essu e ( enced o ha dly
accessible), and highe sho eline he e ogenei y on a i icial han na u al
sho elines (Espinosa e al., 2009; Ri e a-Ing aham e al., 2013;
Os al´
e-Val ibe as e al., 2022, 2023).
Su eys we e made in h ee Ceu a si es, each wi h dolomi ic lime-
s one ip aps and na u al ocky sho es (less han 650 m apa ) (Fig. 1. A).
The ip aps s udied in No h Bay, Cho illo, and Fuen ecaballos we e
olde han 16 yea s and we e cons uc ed in 1935, 1988, and 2006,
espec i ely (Os al´
e-Val ibe as e al., 2018). The e o e, a i icial sub-
s a a a e expec ed o hos climax ben hic communi ies in e ms o
species composi ion and ichness (Hawkins e al., 1983; Coombes, 2011;
Dong e al., 2016). Addi ionally, hese subs a a a e an icipa ed o
suppo ma u e limpe popula ions, as he a e age li espan o he s ud-
ied species is less han 10 yea s (Espinosa e al., 2008; Hen iques e al.,
2012; P usina e al., 2015).
2.2. En i onmen al s udy
The physicochemical desc ip ion o he s udied a eas was ca ied ou
in July 2022 by haphaza dly deploying wo ho izon al 10 m ansec s a
J. Sempe e-Val e de e al.
Es ua ine, Coas al and Shel Science 297 (2024) 108617
3
he uppe midli o al le el in each o he s udied si es and subs a a
(Fig. 1. A). Subs a um inclina ion, he e ogenei y and oughness we e
measu ed a each ansec . He e ogenei y was calcula ed by ho izon ally
deploying a lexible measu ing ape along he uppe midli o al,
ollowing he ock con ou (p o ile) along he whole leng h o he
ansec (10 m linea dis ance). Roughness and inclina ion we e
measu ed a he beginning, in he middle, and a he end o each an-
sec . Roughness was measu ed ollowing he same me hod as he e o-
genei y bu along h ee ho izon al 25 cm linea dis ance ansec s and
using a p o ile gauge wi h 0.5 mm pins o ob ain he ock p o ile (F os
e al., 2005). Bo h he e ogenei y and oughness indexes we e calcula ed
by di iding he ob ained p o iles by he linea dis ance o he sampled
ansec (see Ri e a-Ing aham e al., 2011b; Sedano e al., 2020b).
Inclina ion was measu ed placing a 3 m s ick on he ocky sho e,
pe pendicula o he sho eline and spanning om he in ali o al o he
sup ali o al le el, o measu e he inclina ion angle o he s ick wi h a
digi al clinome e .
The chemical and li hological composi ion o each ansec ock was
s udied by collec ing wo ock chips pe si e and subs a um. These we e
used o con i m he dolomi ic na u e o he a i icial b eakwa e in he
s udied a eas (see Os al´
e-Val ibe as e al., 2023) and he in o ma ion
p o ided by he Geological and Mining Ins i u e o Spain, which iden-
i ies he na u al ock in he a ea as mainly me amo phic, wi h as
gneisses (bio i e schis s), migma i es and po phy i ic g ani oids a No h
Bay, gneisses and migma i ic gneisses a Cho illo, and phylli es and
de o med conglome a es a Fuen ecaballos (Pineda e al., 2013). Rock
chips we e milled and used o calcula e he ock elemen al composi ion
by X- ay luo escence (XRF) using an AXIOS spec ome e . Rock
mine alogical composi ion was es ima ed by X- ay di ac ion (XRD)
using a powde di ac ome e (B uke D8 Ad ance) equipped wi h a
high empe a u e chambe (An on Paa XRK 900) and a as
esponse/high sensi i i y de ec o (B uke Van ec 1) wi h adial Solle
sli s (Val e de e al., 2015).
Wa e exposu e and sho e aspec (o ien a ion) we e ob ained a each
si e and subs a um wi h Google Ea h. Wa e exposu e was quan i ied
using he Fe ch index, which has been success ully employed o p edic
in e idal communi y pa e ns (e.g., Bu ows e al., 2008), and de i es
om an a e age be ween he maximum and e ec i e e ch indices
(Howes e al., 1994). E ec i e e ch (Fe) is calcula ed using he equa ion
Fe =[∑(cos Өi) ×Fi]/∑cos Өi, wi h Өi ep esen ing angles be ween
sho e-no mal and di ec ions 0◦, 45◦le , and 45◦ igh , and Fi as he
dis ance in Km along he ele an ec o , wi h a limi alue o 1000 km
con en ionally used o open ocean. Maximum e ch is he maximum Fi
eco ded when calcula ing Fe. Finally, he wa e exposu e class o each
coas line sec ion is de e mined based on i e ca ego ies: e y p o ec ed
(Fe ch <1), P o ec ed (1–10), semi-p o ec ed (10–50), semi-exposed
(50–500), and exposed (>500) (Howes e al., 1994; Te ´
on-Sigle
e al., 2016).
2.3. Mo phome ic s udy
Adul indi iduals o Pa ella us ica and P. cae ulea, wi h sizes anging
om 1.5 o 4.0 cm (F enkiel, 1975; P usina, 2013), we e andomly
collec ed in May 2022 om wo subs a a: a i icial limes one b eak-
wa e s and na u al ock la s a h ee si es in Ceu a, S ai o Gib al a ,
Spain (Fig. 1. A). A each si e and subs a um, a o al o 25 indi iduals o
each species we e collec ed om he uppe midli o al (P. cae ulea) and
lowe sup ali o al (P. us ica) wi hin a 25 m ansec pa allel o he
sho eline (50 indi iduals pe species and si e). Limpe s we e collec ed
ensu ing ha hei shells we e no excessi ely e oded o he ex en o
losing hei o iginal shape.
A e collec ion, shells we e cleaned and pho og aphed om en al
Fig. 1. A: S udy si es, indica ing he loca ion o he sampled a i icial and na u al subs a a in Ceu a (No h A ica, Spain). B: Landma ks (LM) and semi-landma ks
(S-LM) con igu a ion o he la e al and en al iews depic ing he consensus shape o all sampled indi iduals. The la e al iew is a non-symme ic shape wi h LM1
loca ed a he on end, LM8 on he apex and LM15 a he back end o he shell. These LM a e espec i ely coinciden wi h he LM16, LM 4 and LM23 o he en al
iew. The en al iew is a symme ical con igu a ion wi h he axis o symme y c ossing LM16 ( on o he shell), LM1 ( on o he head), LM4 (apex), LM10
(pos e io end o he hepa opanc ea ic ca i y) and LM23 (back end o he shell). This LM and S-LM con igu a ion was selec ed o e lec he shape con ou o he
bo de o he shell and he bo de o he hepa opanc ea ic ca i y.
J. Sempe e-Val e de e al.
Es ua ine, Coas al and Shel Science 297 (2024) 108617
4
and la e al pe spec i es. The analysis o shell shape was pe o med using
landma k-based (2D) geome ic mo phome ic echniques. The apex,
shell ou line and hepa opanc ea ic ou lines we e cap u ed om he
la e al iew using a non-symme ic con igu a ion wi h 3 landma ks and
22 semi-landma ks (Fig. 1B), and om he en al iew using a sym-
me ic con igu a ion wi h 9 landma ks and 20 semi-landma ks (Fig. 1C).
All specimens we e digi ized by he same obse e (JS-V) using TpsDig2
.2.17. The semi-landma ks used o cap u e con ou s we e laye ed
e enly along con ou cu es be ween landma ks and we e homologa ed
ma hema ically in an i e a i e p ocess (sliding) using TpsRelw .1.53. In
his me hod, he S-LM coo dina es a e slid along he con ou o minimize
he bending ene gy o he landma k con igu a ion (Slice, 2005). Then, a
gene alized P oc us es analysis was applied in which landma k con ig-
u a ions we e o a ed, ansla ed o a common o igin, and scaled o a
uni a y cen oid size o ob ain he P oc us es aligned coo dina es, used
as shape da a (Rohl and Slice, 1990).
2.4. S a is ical analyses
Possible di e ences in shell size among si es and subs a a o
P. us ica and P. cae ulea we e es ed using ANOVAs on cen oid size
da a, a e explo ing he da a o no mali y wi h a Kolmogo o -Smi no
es , and homoscedas ici y wi h a Le ene’s es . These analyses we e
ca ied ou using IBM SPSS S a is ics 22. To accoun o allome y,
mul i a ia e eg essions we e pe o med in Mo phoJ 1.06 b (Klingen-
be g, 2011) o bo h species and each species sepa a ely (Zeldi ch e al.,
2012). The e m “allome y,” was used as de ined by Mosimann (1970):
he pa e n o co a ia ion among mo phological ai s o he ela ion-
ship be ween shape and size componen s. Mo phoJ eg essions a e
compu ed and plo ed a e D ake and Klingenbe g (2008), and o igi-
na e om he eg ession equa ion y =xb +e, whe e y is he andom
ec o o dependen a iables, which in ou case a e he shape a iables
ep esen ed by he P oc us es coo dina es (la e al iew) and he sym-
me ic componen ( en al iew), x is he andom ec o o independen
a iables, which in ou case is he cen oid size (shell size), b is he
ma ix o eg ession coe icien s, and e is he andom ec o o e o
e ec s. The mul i a ia e eg ession sco es a e hen accoun ed wi h he
a iable si =ybi
T
(bi
T
bi)
−0.5
, o ob ain he shape sco e s, which is he
shape a iable ha is mos s ongly associa ed wi h he i- h independen
a iable (x
i
) (see Klingenbe g, 2011). The s a is ical signi icance o he
eg ession was es ed wi h a pe mu a ion es (10,000 ounds) agains
he null hypo hesis o independence. The p esence o allome y was
conside ed i he eg ession was signi ican (p- alue <0.05) and he
eg ession coe icien highe han 5 %. In hese cases, he ec o o
eg ession sco es compu ed by Mo phoJ o all he obse a ions in he
sample was isualized along wi h he shape a ia ions ep esen ed by
he mul iple eg ession, which we e plo ed by econs uc ing hypo-
he ical o ms o a wi e ame connec ing landma ks (wi e ame plo ).
Whene e p esen , allome y componen was elimina ed du ing u he
analyses by wo king wi h he eg ession’s esiduals (Klingenbe g, 2016;
Ou omu o and Johansson, 2017).
Shape da a (PCsco es) was used o pe o m conglome a e o dina-
ions on Mahalanobis dis ances among species, si es and subs a a using
In oS a (Di Rienzo e al., 2020). Subsequen o dina ions and es s we e
made wi h Mo phoJ so wa e, using Disc iminan Func ion Analyses
wi h c oss alida ion o explo e a ia ion be ween wo g oups o ob-
se a ions (species and subs a a) and Canonical Va ia e Analyses as a
gene al analysis o ind he shape ea u es ha bes dis inguish among
mul iple g oups o specimens ( a ia ion among si es) (Klingenbe g,
2011 and e e ences he ein). Disc iminan Func ion and Canonical
Va ia e Analyses a e classical echniques o mul i a ia e s a is ics, and
de ails can be ound in mos ex books o mul i a ia e s a is ics and
mo phome ics (e.g., Rohl and Books ein, 1990; Timm, 2002). In
mul i a ia e mo phome ics, hese a e used o iden i y shape compo-
nen s ha maximize he di e ences in shape be ween and among g oup
o obse a ions ha a e known a p io i (Viscosi and Ca dini, 2011). Fo
he esul ing o dina ions, shape di e ences be ween g oup means and
along canonical axes we e plo ed using wi e ame plo s. Following
hese ou ines, di e ences be ween g oups we e analysed using pe -
mu a ion es s (10,000 pe mu a ions) on P oc us es dis ances (Mahala-
nobis dis ances) o calcula e he Ho elling T-squa e s a is ic o he null
hypo hesis o equal g oup means.
3. Resul s
3.1. En i onmen al s udy
The physicochemical cha ac e iza ion o he sampling a eas high-
ligh ed a highe mac oscale he e ogenei y and su ace oughness o
a i icial subs a a wi hin all si es, excep o oughness in Fuen eca-
ballos (Table 1). O e all, sho e aspec was simila o he a i icial and
na u al a eas o each si e. A No h Bay and Fuen ecaballos, na u al
sho es we e sligh ly s eepe han a i icial sho es; in con as a Cho illo
he a i icial sho e was much s eepe . Fu he mo e, all si es and sub-
s a a we e semi-exposed acco ding o Fe ch index classi ica ion,
al hough he si es acing sou h, pa icula ly Cho illo, we e he mos
wa e exposed si e while No h Bay si e was he leas exposed one.
Finally, subs a a had di e en elemen s and li hological composi ion,
wi h a i icial subs a a being dolomi ic ip ap ocks, and na u al ocks
showing he p o ile o g aphi e, qua z and musco i e- ich me amo phic
ocks (Supplemen a y Table 1).
3.2. Mo phome ic s udy
No indi iduals o Pa ella cae ulea we e ound on he na u al sub-
s a um in No h Bay, so he mo phome ic s udy was ca ied ou wi h a
o al o 275 indi iduals. The cen oid sizes o P. us ica and P. cae ulea
ollowed a no mal dis ibu ion o all si es and subs a a (Kolmogo o -
Smi no : P >0.05 in all es ou pu s) and we e homoscedas ic (Le ene:
P. us ica: F
5,269
=0.57; P =0.722; P. cae ulea: F
4,269
=1.75; P =0.143).
No di e ences in cen oid size we e ound be ween subs a a o
P. us ica (ANOVA: MS =0.85; F
1,269
=2.31; P =0.131) and P. cae ulea
(MS =0.16; F
1,269
=0.40; P =0.527) and among si es o P. cae ulea
(MS =1.01; F
2,269
=2.55; P =0.082). Howe e , cen oid size was highe
in No h Bay han Fuen ecaballos and Cho illo o P. us ica (MS =6.88;
F
2,269
=18.65; P <0.001) (see means and s anda d de ia ions a Sup-
plemen a y Table 2).
Allome ic changes in shell shape p edic ed less han 5 % o he
o e all shape a ia ion when conside ing bo h species (Table 2). How-
e e , when conside ing species sepa a ely, allome ic shell g ow h
occu ed in P. us ica la e al iew, wi h shell heigh inc easing mo e
apidly han leng h as size inc eased, and he en al con ou o
P. cae ulea, in which he inne con ou g ew mo e apidly a ound he
body han he head (Table 2; Supplemen a y Fig. 1). The e o e, allom-
e y was conside ed p esen o P. us ica la e al iew and P. cae ulea
en al iew and subsequen analyses we e ca ied ou wi h he e-
siduals o hese eg essions, conside ed as new size-un ela ed shell shape
a iables.
O e all, di e ences in shape be ween species we e highe han hei
in aspeci ic a ia ion o bo h la e al and en al iews, and highe o
he la e al han he en al iew (see Fig. 2). On he la e al iew, he
mean shell shape o P. us ica is mo e conical, wi h he shell less p o-
jec ed on an e io -pos e io axis, and mo e p ojec ed apex along he
do sal- en al axis, han P. cae ulea (Disc iminan Func ion Analysis: N
=275; Mahalanobis dis ance =4.28; T-squa e =1248.5; P (pe m) <
0.001; see Supplemen a y Table 3; Supplemen a y Fig. 2). On he
en al iew, he shell con ou o P. us ica was gene ally ounde , while
P. cae ulea had a mo e pen agonal shell con ou shape, and he inne
hepa opanc ea ic con ou was sligh ly ounde , and he apex mo e
displacemen o he pos e io pa in P. us ica han P. cae ulea (N =275;
Mahalanobis dis ance =2.98; T-squa e =757.7; P (pe m) <0.001; see
Supplemen a y Table 3; Supplemen a y Fig. 2).
J. Sempe e-Val e de e al.
Es ua ine, Coas al and Shel Science 297 (2024) 108617
5
Table 1
Resul s o he en i onmen al a iables measu ed in each sampled loca ion. * Rock ype was in e ed om he li hological esul s included a Supplemen a y Table 1.
Cell shading in he able is indica i e o cell alues, wi h da ke shading applied o highe alues.
Si e No h Bay Cho illo Fuen ecaballos
Subs a um A i icial Na u al A i icial Na u al A i icial Na u al
He e ogenei y 1.53 1.17 1.59 1.25 1.28 1.23
Roughness 32.80 29.60 32.41 31.17 31.37 31.78
Inclina ion 17.41ᵒ 21.11ᵒ 21.14ᵒ 13.44ᵒ 16.36ᵒ 18.79ᵒ
Fe ch index 71.46 54.49 203.13 213.42 99.11 176.29
Sho e aspec N NW S S SE S
Rock ype* Dolomi e G aphi e Dolomi e Qua z-musco i e Dolomi e Musco i e
Table 2
Reg essions esul s be ween cen oid size as shell size (p edic o a iable), and he P oc us es coo dina es (la e al iew) and symme ic componen ( en al iew) as
shape a iables ( esponse a iables) o accoun o allome y, o all specimens (N =275) and o each species sepa a ely: Pa ella us ica (n =150) and P. cae ulea (n =
125). SS =To al squa e sum; Residual =Residual squa e sum; % p ed = eg ession coe icien . Bold alues indica e he cases in which allome y is accep ed (signi ican
P- alue and a eg ession coe icien highe han 5 %).
La e al iew Ven al iew
SS Residual % p ed P- alue SS Residual % p ed P- alue
All specimens 0.970 0.945 2.53 <0.001 0.536 0.511 4.79 <0.001
P. us ica 0.477 0.427 10.52 <0.001 0.243 0.235 3.43 <0.001
P. cae ulea 0.357 0.346 3.17 0.010 0.233 0.220 5.76 <0.001
Fig. 2. Conglome a e o dina ions depic ing he Mahalanobis a e age dis ances among he sampling loca ions o all indi iduals (P. us ica and P. cae ulea) using he
la e al and en al iews shape da a. The wi e ames o he consensus shapes a e included o P. us ica and P. cae ulea along wi h hei espec i e sample g oups.
J. Sempe e-Val e de e al.

Es ua ine, Coas al and Shel Science 297 (2024) 108617
6
Table 3
Canonical Va ia e Analysis (CVA) on P oc us es coo dina es, showing Mahalanobis dis ances (Md) and P- alues om pe mu a ion es s (P (pe m)) be ween pai s o
si es o he la e al and en al iews o P. us ica and P. cae ulea. NB =No h Bay; Ch =Cho illo; Fc =Fuen ecaballos.
La e al iew Ven al iew
Pa ella us ica Pa ella cae ulea Pa ella us ica Pa ella cae ulea
Md P (pe m) Md P (pe m) Md P (pe m) Md P (pe m)
NB s. Ch 2.01 <0.001 2.68 <0.001 1.84 <0.001 2.22 <0.001
NB s. Fc 1.88 <0.001 3.63 <0.001 2.08 <0.001 2.79 <0.001
Ch s. Fc 2.01 <0.001 1.80 <0.001 2.12 <0.001 1.95 <0.001
Table 4
Disc iminan analyses on P oc us es coo dina es be ween subs a a (a i icial s. na u al) o he la e al and en al iews o Pa ella us ica and P. cae ulea. M-dis ance
=Mahalanobis dis ance; T-squa e =Ho elling’s -s a is ic; P (pe m) =P- alues om pe mu a ion es s.
La e al iew Ven al iew
Mahalanobis dis ance Ho elling’s -s a is ic P (pe m) Mahalanobis dis ance Ho elling’s -s a is ic P (pe m)
P. us ica 2.05 158.22 <0.001 1.44 77.54 0.001
P. cae ulea 2.03 123.35 0.012 1.48 65.29 0.011
Fig. 3. Canonical Va ia e Analyses (CVAs) on P oc us es coo dina es among si es o he la e al iew o P. us ica (A) and P. cae ulea (B) and he en al iew o
P. us ica (C) and P. cae ulea (D). The colou ed ci cum e ences in he CVAs ep esen 95 % con idence ellipses o he a e age o each si e. The wi e ame diag ams
show he a ia ion ob ained in each CVA axis, showing bo h he posi i e and nega i e di ec ion o he de o ma ion, wi h a scale ac o o ±4. Ligh blue indica es he
consensus shape, while da k blue indica es he ±shape ex eme a ia ions. (Fo in e p e a ion o he e e ences o colou in his igu e legend, he eade is e e ed
o he Web e sion o his a icle.)
J. Sempe e-Val e de e al.
Es ua ine, Coas al and Shel Science 297 (2024) 108617
7
Mahalanobis dis ances among indi iduals e ealed in aspeci ic
di e ences among si es and subs a a o bo h s udied species (Table 3;
Table 4). O e all, indi iduals had a speci ic shell shape a each si e.
These di e ences occu ed o he la e al iew in he posi ion o he
apex, which was close o he cen e o he shell a he si es in Sou h Bay:
Cho illo and Fuen ecaballos, and mo e displaced o he on o he
animal in No h Bay o bo h P. us ica (Fig. 3. A) and P. cae ulea (Fig. 3.
B). F om he en al iew, he ela i e size o he hepa opanc ea ic
con ou a ound he head was smalle in Fuen ecaballos and bigge in
Cho illo o bo h species (Fig. 3. C and D). In P. cae ulea, he en al
shape a ied om a ounde shell pe ime e and elonga ed hep-
a opanc ea ic con ou in No h Bay o a mo e pen agonal ou e shell
pe ime e and mo e globula inne con ou in Fuen ecaballos (Fig. 3. D).
Shell shape a ied be ween a i icial and na u al subs a a o
P. us ica and P. cae ulea (Table 4), al hough his a ia ion was gene ally
small and only P. us ica en al iew showed a clea dis inc ion be ween
subs a a (Table 5). None heless, bo h species showed a simila shell
shape a ia ion be ween subs a a (Fig. 4). Fo he en al iew,
P. us ica had a wide hepa opanc ea ic con ou (inne con ou ) a ound
he head and na owe a ound he body, which leaded o a wide space
be ween he oo and he con ou o he shell in na u al han a i icial
subs a a (Fig. 4). Fo he la e al iew, P. us ica showed a highe shell in
na u al han a i icial subs a a. Seemingly, he ela ion be ween he
hepa opanc ea ic con ou a ound he body and he ou e shell p o ile
(ou e con ou ) was also smalle and he la e al shell p o ile was sligh ly
highe in na u al han a i icial subs a a o P. cae ulea (Fig. 4), which
also leaded o a wide gap be ween he oo and he ou e shell con ou
in na u al han a i icial subs a a.
4. Discussion
A consis en mo phological di e ences be ween a i icial and na u al
subs a a o bo h s udied species and ac oss si es (hypo heses H1 and
H2) sugges s ha he e is a common ac o in luencing shell mo phology
ha seg ega es popula ions om na u al e sus a i icial subs a a. In
he p esen s udy, ock li hology, he e ogenei y and oughness we e he
en i onmen al pa ame e s ha mo e clea ly seg ega ed na u al and
a i icial subs a a and could ha e in luenced he obse ed di e ences in
shell mo phology (H3). These ac o s can in luence he abundance and
popula ion s uc u e o pa ellid limpe s, pa icula ly when compa ing
a i icial and na u al subs a a (Espinosa e al., 2011; Ri e a-Ing aham
e al., 2011a; Ba elli, 2016; Cacabelos e al., 2016; Os al´
e-Val ibe as
e al., 2023). Ne e heless, ock ype has a seconda y ole in s uc u ing
ben hic communi ies (Cacabelos e al., 2016, 2019; Sempe e-Val e de
e al., 2023). I s e ec s on limpe s’ mo phology a e s ill poo ly unde -
s ood, and some au ho s ound no di e ences in shell leng h and heigh
when compa ing di e en subs a a (Ba elli, 2016; Ame e al., 2018).
In his s udy, he a i icial subs a a (limes one boulde s) could be
p omo ing a lowe desicca ion s ess han he na u al me amo phic
ocks. Fi s , because he highe he e ogenei y o a i icial subs a a (10
m scale) sugges s ha ip aps could ha e mo e nooks and c annies,
shadowed a eas ha limpe s migh be using o amelio a e desicca ion
and empe a u e s ess du ing low ide (P usina, 2013; Fi h e al.,
2015). Second, because a highe he e ogenei y o he subs a um su ace
a small scales (e.g., oughness) allows less hea ing and mo e wa e
e en ion du ing low ide, e en hough he e ogenei y in he ield exis s
on many scales besides hose es ed in he p esen s udy (Aguile a e al.,
2019; Sempe e-Val e de e al., 2023; Amb ose e al., 2021). Thi d,
because he di e ences in ock li hology de e mine hei wea he ing
a es, oughness, shape, ex u e, we abili y and albedo, and can in u n
in luence desicca ion s ess du ing low ide (Sempe e-Val e de e al.,
2023 and e e ences he ein). Roughness di e ences a e due in pa o
ock mine ology and e osional his o y, o which in e ene biological
wea he ing coupled wi h bioe osion by endoli hic algae bo e in o
calca eous subs a a h ough chemical p ocesses (Sch¨
onbe g and Wis-
shak, 2014; Sempe e-Val e de e al., 2018; Amb ose e al., 2021). This
migh ha e con ibu ed o an inc eased oughness o he s udied
calca eous ock in a mic oscopic scale and migh p o ide an addi ional
eeding esou ce o g azing o ganisms, in addi ion o mic obial ilms on
he su ace (Hills and Hawkins, 1991), mac o-algae (Della San ina e al.,
1993) and mac o-algal de i us (No man e al., 2016). Mo eo e ,
calca eous ock ypes gene ally ha e a highe su ace ee ene gy han
silica- ich ones, which esul s in a highe we ing (Callow and Fle che ,
1994; Amb ose e al., 2021). Finally, he calca eous a i icial dolomi e
was ligh e (highe albedo) han he na u al ocks in he s udied a eas
(JS-V pe s. Obs.), which would imply lowe he mal abso p ion by he
o me om sunligh . In conclusion, all hese ac o s could ha e
con ibu ed o educe he he mal and desicca ion s ess expe ienced on
a i icial subs a a, in luencing limpe s’ pheno ype. I is in e es ing o
no e ha ea lie s udies ha e sugges ed ha a i icial subs a a could
c ea e ho e and d ie condi ions compa ed o na u al subs a a
(Aguile a e al., 2019). This migh be linked o he unique ea u es o he
su aces examined in his s udy, as o he a i icial subs a a, such as
conc e e, would no be as he e ogeneous as he s udied ip aps. Mo e-
o e , na u al ock exhibi s signi ican geog aphical he e ogenei y,
leading o a ange o en i onmen al condi ions, while a i icial sub-
s a es end o show mo e uni o mi y ac oss loca ions when compa ed o
na u al ock. The e o e, mo e esea ch on di e en subs a a and hei
e ec s ac oss geog aphical scales would be needed be o e d awing
conclusions abou he ecological e ec s o subs a um ype.
Rega dless o he high spa ial and esidual a iabili y in Pa ella us-
ica and P. cae ulea, which e lec s he high pheno ypical a iabili y o
bo h s udied species (Belkhodja and Romdhane, 2012; P usina, 2013;
Bouzaza and Mezali, 2018), he e was a common end by bo h species
owa ds a sligh ly inc eased shell heigh and a na owe hep-
a opanc ea ic con ou on na u al subs a a. These a e s a egies adop ed
by limpe s agains he mal and desicca ion s ess (Ve meij, 1973; Ha ley
e al., 2009). A alle shell has a smalle basal su ace a ea pe olume
uni , which educes empe a u e ans e by conduc ion wi h he sub-
s a um, educes he a ea exposed o sunligh adia ion, and migh in-
c ease hea loss by con ec ion (Ha ley e al., 2009). I also educes he
basal pe ime e o he shell, which in u n minimizes wa e loss h ough
Table 5
Classi ica ion/misclassi ica ion ables o c oss alida ion o disc iminan unc ions be ween a i icial and na u al subs a a o Pa ella us ica (n =150) and P. cae ulea
(n =125) la e al and en al iews.
O igin
Pa ella us ica La e al iew Pa ella us ica Ven al iew
Alloca ed o Alloca ion accu acy Alloca ed o Alloca ion accu acy
A i icial Na u al A i icial Na u al
A i icial 52 23 69.3 % 56 19 74.7 %
Na u al 31 44 58.7 % 18 57 76.0 %
Pa ella cae ulea La e al iew Pa ella cae ulea Ven al iew
A i icial 52 23 69.3 % 52 23 69.3 %
Na u al 22 28 56.0 % 23 27 54.0 %
J. Sempe e-Val e de e al.
Es ua ine, Coas al and Shel Science 297 (2024) 108617
8
he bo de o he shell du ing low ide (Ve meij, 1973). Mo eo e , a
highe shell implies a highe la e al a ea in ela ion o basal a ea, which
in u ns inc eases he capaci y o he ex a- isce al ca i y (Ve meij,
1973). This ca i y is u he inc eased by a na owe hepa opanc ea ic
con ou ha inc eases he gap be ween he oo and shell pe ime e and
de e mines he amoun o wa e ha can be e ained a ound he oo
du ing low ide (Ve meij, 1973; P usina, 2013). All his would help
limpe s be e su i e empe a u e and desicca ion s ess in he in e -
idal en i onmen (Ve meij, 1973; Paulo Cab al, 2007; Ha ley e al.,
2009), indica ing ha a i icial subs a a ha e lowe empe a u es and
hence desicca ion s ess han hose na u al subs a a in ou s udy.
Ne e heless, subs a um ype had a clea seconda y ole in in luencing
shell mo phology, since shell shape a ia ion is mos likely de e mined
by adap a ion o he local en i onmen . In ield, en i onmen al
condi ions a e de e mined by a complex in e ac ion o ac o s ha a y
ac oss si es and loca ions, such as sho e aspec , inclina ion, local hy-
d odynamics, wa e ac ion, limi ed esou ces a ailabili y (e.g., ood and
e ugia), as well as pollu ion, collec ion, compe i ion and p eda ion
p essu e (Denny and Blanche e, 2000; Tablado and Gappa, 2001; Ri -
e a-Ing aham e al., 2011a; Ame e al., 2018; Bouzaza and Mezali,
2019; Vasconcelos e al., 2020; Espinosa e al., 2021; Os al´
e-Val ibe as
e al., 2022, 2023). The e o e, u he s udies inco po a ing expe i-
men al manipula ions would be necessa y o u he elucida e he un-
de lying mechanisms d i ing pa e ns o shell a ia ion in limpe
species.
This s udy eco ded he mo pho ypes ha cha ac e ize P. us ica and
P. cae ulea, he high in aspeci ic a iabili y in shell shape o hese
species, and hei allome ic g ow h pa e ns (Belkhodja and Romdhane,
Fig. 4. Disc iminan analyses on shell shape di e ences (P oc us es coo dina es) o he la e al and en al iews o P. us ica and P. cae ulea be ween na u al and
a i icial subs a a. The wi e ame diag ams show he a ia ion ob ained along he disc iminan sco es, showing bo h he posi i e and nega i e di ec ion o he
de o ma ion, wi h a scale ac o o ±3.0. The e o e, he da k blue wi e ame indica es a h ee- imes exagge a ed a e age shape on na u al subs a a, while he ligh
blue indica es he same o a i icial subs a a. (Fo in e p e a ion o he e e ences o colou in his igu e legend, he eade is e e ed o he Web e sion o
his a icle.)
J. Sempe e-Val e de e al.
Es ua ine, Coas al and Shel Science 297 (2024) 108617
9
2012; P usina, 2013; Puig, 2016; Bouzaza and Mezali, 2018). Among
in e idal limpe s, he e is a well-known in e - and in aspeci ic inc ease
in shell heigh /basal a ea a io wi h inc easing sho e le el (Ve meij,
1973; Paulo Cab al, 2007; Ri e a-Ing aham e al., 2011b). Howe e ,
hese changes can also occu h oughou he on ogene ic de elopmen o
hese o ganisms. In he Medi e anean Sea, P. us ica shells exhibi
allome ic shell g ow h, wi h heigh inc easing mo e apidly han
leng h, o educe e apo a i e wa e loss (Paulo Cab al, 2007; P usina,
2013; Ame e al., 2018), and wi h he shell base becoming mo e ci cula
and he apex becoming mo e cen ed (Bensaˆ
ad-Bendjedid e al., 2022),
which has been ela ed o a as e and s onge adhesion o he sub-
s a um and migh be an adap a ion o a high hyd odynamic s ess
en i onmen (Denny and Blanche e, 2000; Paulo Cab al, 2007; Bouzaza
and Mezali, 2019). The same allome ic g ow h, wi h he shell base
becoming mo e ci cula and he apex becoming mo e cen ed, was
ound o P. cae ulea in his s udy. In P. cae ulea, Boukhicha e al. (2010)
desc ibed an allome ic inc ease in shell heigh , which along wi h a
ounde basis would help o igh desicca ion s ess (Paulo Cab al,
2007). Finally, Boukhicha e al. (2010) desc ibed an allome ic inc ease
in adula leng h in P. cae ulea, which has also been p oposed as an
adap a ion o g azing highe sho e le els, whe e algae a e less abundan
and mo e equen ly enc us ing (Paulo Cab al, 2007; Boukhicha e al.,
2010). Finally, his allome ic g ow h migh as well be accompanied by
a displacemen o he home-sca o uppe li o al le els, which a e o en
inhabi ed by g ea e indi iduals o P. Rus ica in he s udy a ea, while he
small indi iduals a e usually in lowe idal le els (JS-V Pe s. Obs.). This
shi in sho e le el be ween ju eniles and adul s occu s in o he species,
and i is equen o ind ju eniles o limpe s occupying di e en niches,
such as idepools and lowe sho e le els, han hose inhabi ed by adul s
(Ri e a-Ing aham e al., 2011b; Espinosa and Ri e a-Ing aham, 2017;
Li o e e al., 2018; Seab a e al., 2020, 2023). None heless, isome ic
g ow h and a nega i e allome ic adula g ow h has also been eco ded
o P. us ica in he colde clima e o NE A lan ic Po ugal (Paulo Cab al,
2007), whe e he he mal and desicca ion s ess migh be a less de e -
minan ac o o su i al.
5. Conclusion
Ou s udy highligh s he complex in e play be ween ock ype and
local en i onmen al condi ions in shaping he mo phology o pa ellid
limpe s and p o ide insigh s in o he adap i e mechanisms ha d i e
shell shape a ia ion in limpe popula ions on subs a a di e ing in
he e ogenei y, oughness and li hology. Coas al sp awl migh ha e
b oad ecological and e olu iona y implica ions on in e idal g aze s,
and i is impo an o unde s and he ecological impac s o coas al
de elopmen on coas al ecosys ems and in he abili y o limpe s o
espond and adap o changing en i onmen al condi ions (Espinosa and
Ri e a-Ing aham, 2017). The e o e, u he esea ch inco po a ing
expe imen al manipula ions, such as Vasconcelos e al. (2021), is
needed o be e unde s and he complex na u e o limpe s’ mo pho-
logical esponses o en i onmen al condi ions. Gi en ha a i icial
subs a a migh p omo e popula ion isola ion and igge selec i e
p essu es in he long e m, wi h di e en popula ions adap ing o spe-
ci ic subs a um cha ac e is ics (Nakano and Ozawa, 2005; Fau elo
e al., 2009; Ri e a-Ing aham e al., 2011b; Sedano e al., 2020b; Espi-
nosa e al., 2021), his s udy unde sco es he need o unde s anding he
mechanisms ha d i e and main ain pheno ypical and geno ypical di-
e si y as a basis o conse ing such popula ions. Finally, he posi i e
impac o a i icial s uc u es on limpe popula ions in his case s udy
and o he s in he s udied a ea, such as Ri e a-Ing aham e al. (2011b),
Ga cía-G´
omez e al. (2014), and Os al´
e-Val ibe as e al. (2022, 2023),
a e geog aphically and s uc u e- ype (dolomi ic b eakwa e ) con ex
speci ic, and hey mus no be used o ad oca e deploymen o a i icial
subs a a (Fi h e al., 2020). Ac ually, coas al sp awl can ha e an
o e all nega i e impac on na i e biodi e si y and may esul in uni o m
selec ion p essu es ha nega i ely impac he limpe popula ions
inhabi ing hem (Mo ei a, 2006; Mo ei a e al., 2006; Fau elo e al.,
2009, 2012; Bulle i and Chapman, 2010; Bu gos-Rubio e al., 2015;
Bishop e al., 2017; Sedano e al., 2020a; Al e e al., 2020; Espinosa
e al., 2021). In he S ai o Gib al a he e a e some bene i s o a i icial
s uc u es o limpe popula ions and conse a ion o a e and endan-
ge ed species (REF), bu his is unlikely o always be he case.
CRediT au ho ship con ibu ion s a emen
Juan Sempe e-Val e de: W i ing – o iginal d a , Visualiza ion,
Fo mal analysis, Da a cu a ion. En ique Os al´
e-Val ibe as: W i ing –
e iew & edi ing, Resou ces, Me hodology, In es iga ion, Funding
acquisi ion. F ee Espinosa: W i ing – e iew & edi ing, Valida ion,
Supe ision, P ojec adminis a ion, In es iga ion, Funding acquisi ion,
Concep ualiza ion. Fede ico M´
a quez: W i ing – e iew & edi ing,
Valida ion, Supe ision, So wa e, P ojec adminis a ion, Me hodology,
In es iga ion, Funding acquisi ion, Fo mal analysis, Da a cu a ion,
Concep ualiza ion.
Decla a ion o compe ing in e es
The au ho s decla e ha hey ha e no known compe ing inancial
in e es s o pe sonal ela ionships ha could ha e appea ed o in luence
he wo k epo ed in his pape .
Da a a ailabili y
Da a will be a ailable a he Uni e siy o Se ille deposi o y
(h ps://idus.us.es/)
Acknowledgemen s
We a e e y g a e ul o Ma kos Digenis o helping wi h he ield
wo k and o he anonymous e iewe s o hei aluable commen s o-
wa ds he imp o emen o he manusc ip . JSV was suppo ed by a FPI
G an (PRE 2018-086266) om Minis e io de Ciencia, Inno aci´
on y
Uni e sidades (P ojec CGL 2017-82739-P) co- inanced by ERDF Eu o-
pean Union and Agencia Es a al de In es igaci´
on, Gobie no de Espa˜
na.
Appendix A. Supplemen a y da a
Supplemen a y da a o his a icle can be ound online a h ps://doi.
o g/10.1016/j.ecss.2024.108617.
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