A New Species of Burrowing Crayfish in Genus Parastacus Huxley, 1879 (Decapoda, Parastacidae) from the Sinos River Basin, Southern Brazil

© 2020 Academia Sinica, Taiwan Open Access Citation: Huber AF, Rockhill ER, Araujo PB, Ribeiro FB. 2020. A new species of burrowing crayfish in genus Parastacus Huxley, 1879 (Decapoda, Parastacidae) from the Sinos River Basin, southern Brazil. Zool Stud 59:47. doi:10.6620/ZS.2020.59-47. BACKGROUND The genus Parastacus comprises 14 species distributed in the southern portion of South America, specifically Brazil, Uruguay, Argentina and Chile. Twelve species are registered in Brazil, five of which are endemic to the state of Rio Grande do Sul (RS) and three to the state of Santa Catarina (SC) (Ribeiro et al. 2016; Ribeiro and Araujo 2017; Ribeiro et al. 2017; Huber et al. 2018; Miranda et al. 2018; Ribeiro et al. 2020). Most Parastacus species have strong burrowing habits and build complex underground tunnels in wetlands (Buckup and Rossi 1980; Noro and Buckup 2010; Ribeiro et al. 2016 2017). The singularity of the burrowing behavior and habitat requirements of freshwater crayfish along with anthropogenic impacts may increase the risk of extinction and previous studies have suggested the species be classified as threatened (Almerão et al. 2015; Richman et al. 2015; Ribeiro et al. 2020). Specifically, in the Sinos River Basin (SRB), located in the state of Rio Grande do Sul, several human activities have been reported to impact native fauna, including crayfish (Rechenmacher et al. 2010; Oliveira et al. 2013; Bianchi et al. 2015; Pedde et al. 2015; Steffens et al. 2015; Miranda et al. 2018; Moser et al. 2018). In this contribution, we describe a new burrowing species of Parastacus from a swamp forest in the SRB Region in the state of Rio Grande do Sul. In addition, the habitat characterization and a risk assessment for the species based on the IUCN Red List Criteria are also presented. A New Species of Burrowing Crayfish in Genus Parastacus Huxley, 1879 (Decapoda, Parastacidae) from the Sinos River Basin, Southern Brazil Augusto F. Huber1, Emily R. Rockhill1, Paula B. Araujo1, and Felipe B. Ribeiro1,* 1Programa de Pós-Graduação em Biologia Animal (PPGBAN), Departamento de Zoologia (Laboratório de Carcinologia), Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, State of Rio Grande do Sul, Brazil. *Correspondence: E-mail: [email protected] (Ribeiro) E-mail: [email protected] (Huber), [email protected] (Rockhill), [email protected] (Araujo) Received 3 June 2020 / Accepted 4 July 2020 / Published 3 August 2020 Communicated by Benny K.K. Chan In this contribution, we describe a new species of burrowing crayfish of the genus Parastacus from a swamp forest in the state of Rio Grande do Sul, southern Brazil, and evaluate its conservation status according to the IUCN Red List Criteria (sub-criterion B1). Parastacus macanudo sp. nov. differs from all other congeneric species in that it has a single row of verrucous tubercles irregularly distributed in the dorsal surface of the palm of chelipeds and epistome median section with a longitudinal groove. The extent of occurrence (EOO) was estimated to be ~1,312 km2 and the species was recorded in only one location in the Sinos River basin. The main threat identified was a continued decline in habitat quality, resulting from pollution in the river and deforestation. We know only one point of occurrence of Parastacus macanudo sp. nov., and suggest that it be categorized as Data Deficient. Key words: Conservation, Freshwater crayfish, Neotropical region, Taxonomy, Parastacoidea. Zoological Studies 59:47 (2020) doi:10.6620/ZS.2020.59-47 1 © 2020 Academia Sinica, Taiwan MATERIALS AND METHODS Specimens were collected from one small section of a swamp forest inside the municipal natural park Imperatriz Leopoldina, in the municipality of São Leopoldo, state of Rio Grande do Sul, Brazil (29°45'40.7"S, 51°07'47.6"W). We used a yabby pump (7 cm × 72 cm) and manual excavation to obtain crayfish specimens and some information about the structure of their burrows. The type material was deposited in the Museu Nacional Rio de Janeiro (MNRJ), Rio de Janeiro, Brazil, and in the Carcinological Collection of the Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Rio do Grande do Sul (UFRGS), Porto Alegre, Brazil. Drawings were prepared with the aid of a stereomicroscope fitted with a camera lucida. Illustrations were prepared using nanquim ink, then scanned. The plates were made in Adobe Photoshop CS6. All measurements were performed with vernier calipers with 0.1 mm accuracy and a millimetric ocular on a stereomicroscope. Morphological descriptions follow Ribeiro et al. (2016) and setae classification follows Horn et al. (2008). Size and shape of the S2 pleura were defined according to Ribeiro et al. (2016). Sex was identified based on the morphology of the gonopores according to Rudolph (1997). The taxonomic classification followed Crandall and De Grave (2017). Branchial count followed Huxley (1879). The burrowing behavior and the burrow structure were classified according to Hobbs (1942) and Horwitz and Richardson (1986), respectively. Hobbs (1942) categorizes crayfish burrowing behaviour in three groups (primary, secondary and tertiary) based on the complexity of the burrow structure, the connection to open waters, seasonality and reproductive period and time that the crayfish spends inside the burrow. Horwitz and Richardson (1986) classification takes into account how the burrow interacts with surface water and the water table: type 1 burrows occur in or are directly connected to water bodies; type 2 burrows are connected to the water table; and type 3 burrows are independent of the water table. The extinction risk of the new species was evaluated according to the B1 sub-criterion of the International Union for Conservation of Nature - IUCN (IUCN 2012). This sub-criterion takes into consideration the estimated Extent of Occurrence (EOO) or the estimated Area of Occupancy (AOO), both of which were calculated in the QGIS 3.10.3 program (QGIS Development Team 2019). The EOO was calculated based on the hydrographic basins according to the Otto Bacias shape method (level 5) (ANA 2007) and the AOO based on a map of the park area and a 2 × 2 km2 grid (SEMA 2020). RESULTS TAXONOMY Infraorder Astacidea Latreille, 1802 Superfamily Parastacoidea Huxley, 1879 Genus Parastacus Huxley, 1879 Parastacus macanudo sp. nov. (Figs. 1–5) urn:lsid:zoobank.org:act:436143C1-7B31-42DF-B1C1A6F96447A100 Type series: Holotype: adult male, Brazil, Rio Grande do Sul, São Leopoldo, Parque Imperatriz Leopoldina (29°45'40.7"S, 51°07'47.6"W) 20/VII/2018, coll. A.F. Huber & F.B. Ribeiro (MNRJcarcino 029877). Paratypes: 1 male, same data as holotype (MNRJcarcino 029878); 2 males, same data as holotype (UFRGS 6672). Comparative material analyzed: Brazil, Rio Grande do Sul: P. brasiliensis: 1 male, Sítio do Mato, Zona Sul, Porto Alegre (-30.114176S; -51.1428W), 22/III/2014, coll. M. Pasolius, (UFRGS 5868); three females, Mariana Pimentel (30°20'00"S, 51°22'39"W), coll. N.F. Fontoura (UFRGS 2338); P. caeruleodactylus: 3 males and 4 females, Dom Pedro de Alcântara, RPPN Mata do Professor Baptista (29°23'06"S, 49°50'20"W), 12/I/2019 (UFRGS 6677); one male, Dom Pedro de Alcântara, RPPN Mata do Professor Baptista (29°23'06"S, 49°50'20"W), 16/IV/2014, col. D.C. Kenne & K.M. Gomes (UFRGS 5934, PARATYPE); Santa Catarina: P. tuerkayi - male, Brazil, Santa Catarina, Penha, Beto Carrero World (26°48'10"S, 48°37'02"W), 04/IX/2013, coll. K.M. Gomes & F.B. Ribeiro (UFRGS 6438), 2 males and 1 female, Brazil, Santa Catarina, Penha (26°47'50.2"S, 48°37'42.7"W), 12/I/2019, coll. F.B. Ribeiro, K.M. Gomes & A.F. Huber (UFRGS 6678). Etymology: Named based on the regional expression “macanudo”, typical of the state of Rio Grande do Sul, which means powerful, strong and admirable. It refers to the large chelipeds of this species, which is an indicative of the strong burrowing capacity. We also suggest the common name “macanudo crayfish” for this species. Diagnosis: Narrow front with short triangular rostrum. Rostral apex shaped as inverted “U”, with an inconspicuous and blunt spine. Suborbital angle > 90° and unarmed. Postorbital carinae inconspicuous. Cervical groove weakly V-shaped. Areola narrower page 2 of 13Zoological Studies 59:47 (2020) © 2020 Academia Sinica, Taiwan than rostral basis and barely discernible. Telson subrectangular with sharp spines on lateral margins. Mandible with caudal molar process bicuspidate with one cephalodistal cusp and one small and sharp distoproximal cusp. S2 pleurae low and long with deep groove parallel to margin. Internal ventral border of basal article of antennule without sharp spine. Description of holotype: Rostrum. triangular, wider than long (RW 85.4% of RL), short (12.8% of CL), reaching proximal portion of the second article of the antennular peduncle (Fig. 1A–C). Dorsum straight, apex inverted “U”-shaped, ending in a tiny straight blunt spine (Fig. 1B, C). Few plumose setae on lateral margins. Carinae almost straight, prominent and narrow, extending back to carapace, surpassing rostral basis; rostral carinae sides convergent and rostral carinae basis divergent. (Fig. 1B, C). Cephalon: Carapace lacking spines or tubercles. CeL 76% of CL. Eyes small (CMW 57.6% of OW); suborbital angle > 90°, unarmed (Fig. 3C). Front narrow (FW 34.6% of CW). Postorbital carinae longer than rostral carinae (RCL 77% of POCL) and weakly prominent. Lateral cephalic edge with moderate setation (Fig. 1A–C). Thorax: Carapace laterally compressed, deep and narrow (CD 58.1% of CL; CW 53.7% of CL). Cervical groove weakly V-shaped. Branchiocardiac grooves inconspicuous (Fig. 1A). Areola narrower than rostral basis, 2.87x as long as wide (35.6% of CL) (Fig. 1A). Pleon: Lacking spines or tubercles, long and wide (PL 83.9% of CL; PW 80.8% of CW), smooth, covered with small setae on pleural margins (Fig. 1A). Pleural somites with rounded posterior margins. S1 pleurae with a large distal lobe not overlapped by S2 pleurae. S2 pleurae low and short with shallow groove parallel to margin (Fig. 1D). Tailfan: Telson uniformly calcified, subrectangular, longer than wide (TeW 76.8% of TeL), with sharp spines on lateral margins; rounded distal margin with abundant long plumose setae and short simple setae. Dorsal surface with tufts of short setae and inconspicuous dorsomedian longitudinal groove (Fig. 1E). Uropod protopod bilobed, with rounded and unarmed margins; proximal lobe largest. Exopod lateral margin bears a small and sharp spine, mid-dorsal carina few prominent, ending in a very sharp spine. Transverse suture (diaeresis) straight, with eight dorsolateral spines (outer) and four dorsolateral spines (inner) on right exopod and six dorsolateral spines (outer) and four dorsolateral spine (inner) on the left exopod. Endopod, mid-dorsal carina few prominent, ending in a very sharp spine; lateral margin with one sharp spine at level of exopod transverse suture (Fig. 1E). Epistome: Anterolateral section with small conical projection in both sides, the right side with small tubercle near the basis of the conical projection. Posterolateral section smooth and with deep lateral grooves converging to the basis of the anteromedian lobe. Median section with a longitudinal groove. Anteromedian lobe pentagonal, 1.1x longer than wide, apex acute and straight with some serrated setae, surpassing median part of antepenultimate article of antennal peduncle; dorsal surface concave and basis with a deep groove (Fig. 2A). Thoracic sternites: SLP4 small and very close to each other, median keel present and not inflated; SLP5 smallest and close to each other, median keel present and not inflated; SLP6 larger than SLP4, SLP5 and SLP8 with a slightly concave surface, median keel inflated; SLP7 largest and with surface slightly concave, median keel inflated, bullar lobes absent; SLP8 small, median keel absent, vertical arms of paired sternopleural bridges separated to each other, bullar lobes close to each other and clearly visible (Fig. 2B, C). Antennule: Internal ventral border of basal article unarmed (Fig. 2A). Antenna: When extended back reaching the posterior margin of the carapace. Antennal scale widest at distal to midlength, reaching proximal margin of third antennal article, ASW 51.1% of ASL (Fig. 2A, D), lateral margin straight and distal spine well developed. Coxa with prominent carina above nephropore and two blunt spines with different sizes laterally distributed. Basis unarmed (Fig. 2A). Mandible: Cephalic molar process molariform, caudal molar process bicuspidate with one cephalodistal cusp and one sharp distoproximal cusp. Incisive lobe with nine teeth. The second tooth from the anterior margin is the largest (Fig. 2E). Third maxilliped: Ischium with few setiferous punctuations on outer margin and ventral surface (Fig. 2F); dorsal surface without setae (Fig. 2G); crista dentata bearing 22 teeth in both right and left ischia (Fig. 2F, G). Merum, dorsal surface glabrous. Merum ventral surface sparsely covered by long smooth simple setae in the median region and with serrated setae on the inner margin (Fig. 2F); Exopod longer than ischium, with flagellum reaching proximal margin of merum and with tuft of long and composed setae in the last articles (Fig. 2F, G). First pair of pereiopods (chelipeds): Large and subequal, laterally flattened (RPrT 28.3% of RPrL; LPrT 27.6% of LPrL) (Figs. 1A, 2I). Ischium ventral surface with 11 and eight tubercles in the right and left respectively. Merus: right merus (RML) 53.4% of propodus length (RPrL); left merus (LML) 51.5% of propodus length (LPrL); ventral surface with two longitudinal series of tubercles: inner series with 16 page 3 of 13Zoological Studies 59:47 (2020) © 2020 Academia Sinica, Taiwan Fig. 1. Parastacus macanudo sp. nov., holotype. A, habitus dorsal view; B, cephalon dorsal view; C, cephalon lateral view; D, first, second and third pleonal pleura; E, telson and uropods dorsal view. Scale bars: A = 1 cm; B, C and E = 3.33 mm; D = 2.5 mm. page 4 of 13 Zoological Studies 59:47 (2020) © 2020 Academia Sinica, Taiwan Fig. 2. Parastacus macanudo sp. nov., holotype and paratypes. A, epistome (holotype); B, thoracic sternites and gonopores (holotype); C, thoracomere 8, caudal view (holotype); D, antennal scale lateral view (paratype 1); E, mandible (paratype 1); F, third maxilliped ventral view (paratype 1); G, third maxilliped dorsal view (paratype 1); H, first pereiopod lateral view (holotype); I, first pereiopod dorsal view (holotype); J, second pereiopod lateral view (holotype). Scale bars: A, C, H and J = 3.33 mm; B and I = 5 mm; D = 1.6 mm; E, F and G = 2.5 mm. page 5 of 13Zoological Studies 59:47 (2020) © 2020 Academia Sinica, Taiwan Fig. 3. Parastacus macanudo sp. nov., living specimens (holotype). A, habitus dorsal view; B, living specimen in the habitat; C, living specimen placed in aquarium. Scale bar: A = 10 mm. page 6 of 13Zoological Studies 59:47 (2020) © 2020 Academia Sinica, Taiwan tubercles, outer 12, plus 13 mesial tubercles irregularly distributed on right merus; inner series with 14 tubercles, outer 15, plus 14 mesial tubercles irregularly distributed on left merus. Dorsal and midventral spines present and blunt. Carpus with dorsomedial surface not divided longitudinally by groove (Figs. 1A, 2I). Internal dorsolateral margin with row of tubercles, increasing in size distally; inner surface with 19 small mesial tubercles. Carpal spine present and blunt (Fig. 2I). Propodus width (RPrW and LPrW) 38.1% of length in right cheliped and 41.9% in left cheliped. Dorsal surface of palm with a single row of verrucous tubercles irregularly distributed (Fig. 2H, I). Inner margin without tubercles. Ventral surface bearing two rows of squamose tubercles, surpassing the beginning of the fixed finger (Fig. 2H). Dactylus moving subvertically, right dactylus (RDL) 64.5% of propodus length (RPrL), left dactylus (LDL) 61.8% of left propodus (LPrL); dorsal surface with few squamose tubercles in the proximal portion (Fig. 4I). Cutting edge of fingers visible. Fixed finger with seven teeth, second and third teeth largest in the right cheliped. Dactylus with nine teeth, second tooth largest (Fig. 2H, I). Ten teeth in both fixed finger and dactylus of the left cheliped. Second pair of pereiopods: Dorsal surface of dactylus and ventral and dorsal surface of carpus and propodus with moderate covering of simple long setae (Fig. 2J). Gonopores: Presence of both genital apertures on coxae of third and fifth pairs of pereiopods. Female gonopores semi-ellipsoidal (maximum diameter 1.18 mm) with well-calcified membrane. Male gonopores rounded, opening onto the apical end of a small, fixed, calcified and truncated phallic papilla, close to the inner border of the ventral surface of coxae of the fifth pair of pereiopods. Male cuticle partition present (Fig. 2B). Branchial count: 20 + epr + r. Branchial arrangement follows the same described by Huxley (1879) and Hobbs (1991) with the epipod of the first maxilliped with rudimentary podobranchial filaments. Measurements: Holotype male, CL 23.42 mm and TL 51.11 mm. In type series, CL ranging from 40.36 to 51.11 mm (45.83 ± 4.46 mm). FW/CW: 0.3 ± 0.02 (min: 0.33; max: 0.38). RL/RW: 1.10 ± 0.19 (min: 0.91; max: 1.33). CMW/OW: 0.7 ± 0.1 (min: 0.57; max: 0.79). Postorbital carina longer than rostral carina in all specimens analyzed. CW/PW: 1.18 ± 0.06 (min: 1.09; max: 1.24). AreW/RW: 0.90 ± 0.08 (min: 0.83; max: 1.02) (Table 1). Color of living specimens: Rostrum dark brown or dark greenish brown. Cephalothorax anterior and lateral regions olive green to greenish brown with shades of light brown. First pair of pereiopods dark greenish brown externally and light brown internally. Pereiopod pairs 2–5 light brown. Dorsal pleon and taifan olive green to greenish brown with shades of light brown (Fig. 3). Variations in type-series: All paratypes present both masculine and feminine gonopores in the same individual. Male paratypes also present female gonopores semi-ellipsoidal (average maximum diameter 1.05 mm) covered by a calcified membrane. Male gonopores are very similar in all male paratypes. The apical spine of the rostrum and carpal spine are larger in the paratypes. The number of teeth in the crista dentata ranges from 20 to 22 in the left ischium and from 20 to 29 in the right ischium of the third maxilliped in the paratypes. Habitat and Ecology: Parastacus macanudo sp. nov. was collected in a small fragment (approximately 500 m2) of a swamp forest located inside the municipal park Imperatriz Leopoldina in the lower part of the SRB, in the state of Rio Grande do Sul (Fig. 5). This physiographic region is an ecotone of the biomes Atlantic Forest (seasonal semi-deciduous forest) and Pampa (savanna), more precisely denominated as Ecologic Tension Area (Mauhs 2013). The vegetation is composed predominantly by trees of Anacardiaceae (“Pau-Ferro”, Myracrodruon balansae), Arecaceae (“Jerivá”, Syagrus romanzoffiana), Fabaceae (“Grápia”, Apuleia leiocarpa), Lauraceae (“Canela”, Ocotea spp.), Meliaceae (“Camboatá”, Guarea macrophylla), Moraceae (“Cincho”, Sorocea bonplandii) and Sapindaceae (“Camboatá Branco”, Matayba elaeagnoides) (E. Rosseto pers. comm.). Additionally, some small-grasses and bushes (Poaceae, Fabaceae, Asteraceae and Cyperaceae) can also be found in the area. The soil is classified as Neossols Fluvic Eutrophic Ta (Santos et al. 2011) and is composed of clay and temporarily flooded depending on river level. According to the burrows and characteristics of the habitat, P. macanudo sp. nov. can be identified as a primary burrower following Hobbs’ (1942) classification. Burrows can reach a depth up to 1m and with 1–4 branches. Chimneys are huge and can reach up to 20 cm high and 10 cm wide (Fig. 4C). Burrows can be identified as type 2 according to Horwitz and Richardson’s (1986) classification. Distribution: Parastacus macanudo sp. nov. appears to have limited distribution, being registered only in the municipality of São Leopoldo, state of Rio Grande do Sul, southern Brazil (Fig. 5). Conservation status: Data Deficient. The EOO was estimated as comprising approximately 1,312 km2 (B1) and the AOO was calculated at 12 km2 (B2). This species follows only the subitem b(iii): continuing decline observed in quality of habitat. page 7 of 13Zoological Studies 59:47 (2020) © 2020 Academia Sinica, Taiwan DISCUSSION Morphology Parastacus macanudo sp. nov. is morphologically similar to P. brasiliensis (von Martens, 1869), P. caeruleodactylus Ribeiro & Araujo in Ribeiro et al., 2016 and P. tuerkayi Ribeiro, Huber & Araujo in Ribeiro et al. 2017 in the general shape of rostrum, length of the rostral and postorbital carinae, number of teeth in the incisive process of the mandible and in the shape of telson (Table 2). The main differences are related to Fig. 4. Parastacus macanudo sp. nov., habitat and burrows. A, swamp forest; B, single burrow opening (white arrow); C, chimney. page 8 of 13Zoological Studies 59:47 (2020) © 2020 Academia Sinica, Taiwan the size of the apical spine of the rostrum (Table 2). The lack of spine in the internal ventral border of the basal article of antennules is shared only by P. macanudo sp. nov. and males of P. tuerkayi (Ribeiro et al. 2017) (Table 2). Parastacus macanudo sp. nov. differs from all other congeneric species in having a single row of verrucous tubercles irregularly distributed in the dorsal surface of the palm of chelipeds and epistome median section with a longitudinal groove (Figs. 1A, 2A, I; Table 2). Habitat and Ecology The seasonal semi-deciduous forest in the SRB is present near the water bodies in the drainage lines, which normally occur between small and smooth hills known as “coxilhas”, where the savanna vegetation can be found. This vegetation is categorized by the loss of the leaves during the winter caused by the process of “physiological drought” (Veloso and Goes-Filho 1982; Teixeira et al. 1986). The Neossols Fluvic Eutrophic Ta is common near rivers and drainages, where the land is flat, it has a high clay composition, high frequency and tendency to be flooded and with high amount of organic matter (AGEITEC 2020). This is reflected in the habitat where the specimens were collected: a temporarily flooded area with a large amount of organic matter derived from leaf decomposition and with several crayfish chimneys (Fig. 4). Regarding the burrowing behavior and burrows, P. macanudo sp. nov. can be considered a primary burrower with type 2 burrows due to the depth and complexity of its tunnels, which can reach the water table. This indicates that burrow occupation is permanent, and it serves as a shelter against desiccation and predators and provides the crayfish with food Table 1. Measurements (mm) of the type series of Parastacus macanudo sp. nov. For abbreviations, see MATERIALS AND METHODS Holotype Paratype 1 Paratype 2 Paratype 3 (MNRJcarcino 029877) (MNRJcarcino 029877) (UFRGS 6672) (UFRGS 6672) Sex M M M M TL 51.11 46.88 44.95 40.36 CL 23.42 23.49 22.63 20.17 CW 12.58 10.35 10.16 9.49 CD 13.61 12.7 12.34 10.4 CeL 17.78 15.18 15.29 13.49 RL 2.99 2.39 2.68 2.43 RW 3.5 3.2 2.69 2.22 RCL 4.89 3.54 3.58 3.46 CMW 1.29 1.21 1.18 1.13 OW 2.24 1.57 1.49 1.52 POCL 6.35 5.54 5.59 4.23 FW 4.36 4.02 3.61 3.17 ASL 2.78 2.5 2.55 2.28 ASW 1.42 1.17 1.12 1.13 AreL 8.35 7.58 7.58 6.17 AreW 2.91 2.76 2.75 2.04 LPrT 7.24 4.36 6.04 3.09 LPrL 26.19 15.24 21.59 12.06 LPrW 10.97 7.95 9.96 5.89 LDL 16.18 9.34 12.19 7.31 LML 13.49 9.21 10.43 8.37 RPrT 7.13 6.67 2.54 3.16 RPrL 25.22 20.68 12.75 12.15 RPrW 9.61 10.43 5.46 5.88 RDL 16.27 11.44 8.05 7.72 RML 13.46 10.03 8.48 8.42 PL 19.64 18.3 17.11 15.38 PW 10.17 9.43 8.72 7.79 TeL 7.75 6.87 6.66 6.14 TeW 5.95 5.35 5.32 4.9 page 9 of 13Zoological Studies 59:47 (2020)