Phylogenetic Appraisal of Lysiosquillidae Giesbrecht, 1910, and a New Species of Lysiosquilloides Manning, 1977, from Taiwan (Crustacea: Stomatopoda: Lysiosquilloidea)

© 2022 Academia Sinica, Taiwan Open Access Phylogenetic Appraisal of Lysiosquillidae Giesbrecht, 1910, and a New Species of Lysiosquilloides Manning, 1977, from Taiwan (Crustacea: Stomatopoda: Lysiosquilloidea) Shane T. Ahyong1,2,* and Chia-Wei Lin3,4 1Marine Invertebrates, Australian Museum, 1 William St., Sydney, NSW 2010, Australia 2School of Biological, Earth and Environmental Sciences, University of New South Wales, Kensington, NSW 2052, Australia. *Correspondence: E-mail: [email protected].au (Ahyong) 3Department of Exhibition, National Museum of Marine Biology and Aquarium, 2 Houwan Road, Checheng, Pingtung, 944, Taiwan. E-mail: [email protected].tw (Lin) 4Institute of Marine Biology, National Dong Hwa University, Hualien 974, Taiwan Received 15 October 2021 / Accepted 4 February 2022 / Published 5 May 2022 Communicated by Benny K.K. Chan The mantis shrimp family Lysiosquillidae includes the largest known stomatopods and presently includes three genera: Lysiosquilla Dana, 1852, Lysiosquillina Manning, 1995, and Lysiosquilloides Manning, 1977. Since 1995, new species assigned to all three lysiosquilloid genera have been recognised: Lysiosquilla manningi Boyko, 2000, Lysiosquillina lisa Ahyong & Randall, 2001, Lysiosquilla colemani Ahyong, 2001, Lysiosquilla suthersi Ahyong, 2001, and Lysiosquilloides mapia Erdmann & Boyer, 2003, and Lysiosquilla isos Ahyong, 2004. Lysiosquillina lisa, Lysiosquilla campechiensis Manning, 1962 and Lysiosquilla suthersi, however, proved problematical to assign to genera owing to the possession of characters intermediate between Lysiosquilla sensu stricto and Lysiosquillina sensu stricto. In particular, species that are transitional between Lysiosquilla and Lysiosquillina challenge the validity of the latter genus. Here, we reassess the status and composition of the lysiosquillid genera by cladistic analysis of all known species in the family. Lysiosquillina is synonymized with Lysiosquilla and a new species of Lysiosquilloides is described from Taiwan. A key to the species of Lysiosquilloides is provided. Key words:Mantisshrimp,Indo-WestPacific,Phylogeny,Systematics,Taxonomy,Coralreef. BACKGROUND The mantis shrimp superfamily Lysiosquilloidea presently comprises Lysiosquillidae Giesbrecht, 1910; Coronididae Manning, 1980; Nannosquillidae Manning, 1980; and Tetrasquillidae Manning & Camp, 1993, united by the subquadrate propodi of maxillipeds 3 and 4, absence of a distinct median carina on the telson, and the antizoeal early larva (Ahyong and Harling 2000; Ahyong et al. 2014). Lysiosquilloids typically occupy deep vertical burrows in soft substrates but unlike members of most other stomatopod groups, they seldom leave their burrows, instead ambushing prey from the burrow mouth. As in callianassoid axiideans (Decapoda), lysiosquilloid morphology is commensurate with the cryptic, infaunal lifestyle: the body is dorsoventrally flattened, weakly calcified and generally loosely articulated, permitting great flexibility within the confines of the burrow. Lysiosquillidae includes some of the largest known stomatopods (exceeding total length 380 mm), most of which are boldly marked with light and dark transverse bands (Ahyong 2001). Within Lysiosquilloidea, synapomorphies of Lysiosquillidae include the absence of posterolateral spines on Citation: Ahyong ST, Lin CW. 2022. Phylogenetic appraisal of Lysiosquillidae Giesbrecht, 1910, and a new species of Lysiosquilloides Manning, 1977, from Taiwan (Crustacea: Stomatopoda: Lysiosquilloidea). Zool Stud 61:12. doi:10.6620/ZS.2022.61-12. Zoological Studies 61:12 (2022) doi:10.6620/ZS.2022.61-12 1 © 2022 Academia Sinica, Taiwan abdominal somite 6, an unfolded proximodorsal margin on the uropodal endopod, intermediate and lateral primary teeth fused into the telson margin, and low, rounded intermediate denticles on the telson (Ahyong and Harling 2000; Ahyong 2001). Until 1995, two genera, Lysiosquilla Dana, 1852, and Lysiosquilloides Manning, 1977, were recognized in Lysiosquillidae. Lysiosquilloides was distinguished from Lysiosquilla primarily on the basis of the articulated apices of the submedian teeth of the telson and the low and blunt, instead of spinous dorsal processes of the antennular somite. Manning (1995) further divided Lysiosquilla based on antennal characters, erecting Lysiosquillina for three species with a broad, ovate antennal scale (length about 2.5 × width) and absence of the dorsomesial spine on the antennal protopod (Fig. 1A), and restricting Lysiosquilla to species having a mesiodorsal spine on the antennal protopod and a slender antennal scale (length ≥ 3.0 × width) (Fig. 1D). Thus, Lysiosquillidae presently includes three genera: Lysiosquilla, Lysiosquillina and Lysiosquilloides (see Manning 1995; Ahyong 2001). Since 1995, new species assigned to all three lysiosquilloid genera have been recognised: Lysiosquilla manningi Boyko, 2000, Lysiosquillina lisa Ahyong & Randall, 2001, Lysiosquilla colemani Ahyong, 2001, Lysiosquilla suthersi Ahyong, 2001, and Lysiosquilloides mapia Erdmann & Boyer, 2003, and Lysiosquilla isos Ahyong, 2004. Lysiosquillina lisa, Lysiosquilla campechiensis Manning, 1962, and Lysiosquilla suthersi, however, proved problematical to assign to genera owing to the possession of features intermediate between Lysiosquilla sensu stricto and Lysiosquillina sensu stricto (see Ahyong and Randall 2001; Ahyong 2001; Fig. 1B, C). The presence of species transitional between Lysiosquilla and Lysiosquillina challenges the validity of the present generic system. In the present study, the status and composition of the lysiosquillid genera are tested by cladistic analysis of all known species of the family, and a new species of Lysiosquilloides is described from Taiwan. MATERIALS AND METHODS Taxonomy Morphological terminology and size descriptors generally follow Ahyong (2001 2012). Specimens are measured in millimetres (mm). Total length (TL) is measured along the dorsal midline from the apex of the rostral plate to the apices of the submedian teeth of the telson. Carapace length (CL) is measured along the dorsal midline and excludes the rostral plate. Fig. 1. Right antenna. A, Lysiosquilla maculata (Fabricius, 1793) (formerly Lysiosquillina), male, TL 162 mm, Queensland, Australia, AM P14919; B, Lysiosquilla lisa (Ahyong & Randall, 2001) comb. nov. (formerly Lysiosquillina), male holotype, TL 295 mm, Bali, Indonesia, MZB Cru1444; C, Lysiosquilla suthersi Ahyong, 2001, male holotype, TL 150 mm, Queensland, Australia, QM W24225; D, Lysiosquilla scabricauda (Lamarck, 1818), male TL 210 mm, Key West Florida, AM P45739. Scale: A = 7.0 mm, B = 3.5 mm, C = 12.0 mm, D = 5.0 mm. Abbreviations: mesial papilla (mp), anteromesial lobe (aml). page 2 of 14Zoological Studies 61:12 (2022) © 2022 Academia Sinica, Taiwan The corneal index (CI) is given as 100CL/corneal width. The propodal index (PI) of the raptorial claw is given as 100CL/propodus length. The genus names, Lysiosquilla, Lyiosquillina and Lysiosquilloides are abbreviated L., Ln., and Ls., respectively. The holotype of Lysiosquilloides taiwanica sp. nov. is deposited in the National Museum of Marine Biology and Aquarium, Kenting, Taiwan (NMMBA). Phylogenetic analysis All 20 recognised lysiosquillid species (including Lysiosquilloides taiwanica sp. nov.) were included as terminals. Although Lysiosquilloidea and Erythrosquilloidea are accepted as sister-groups, the phylogenetic position of Lysiosquillidae with the superfamily is currently unresolved. Phylogenetic analyses variously recover lysiosquillids as the sister group to Nannosquillidae or as sister to the remaining lysiosquilloids (Ahyong 1997; Ahyong and Harling 2000; Porter et al. 2010; Van Der Wal et al. 2017). Therefore, the analysis was rooted to Erythrosquilla megalops Manning & Bruce, 1984, but with a representative nannosquillid (Acanthosquilla multifasciata (Wood-Mason, 1895)) and tetrasquillid (Heterosquilla platensis (Berg, 1900)) included in the in-group. Character states of other ingroup species were scored from specimens in the collections of the Australian Museum, Sydney (AM) (Lysiosquilla colemani Ahyong, 2001, Lysiosquilla isos Ahyong, 2004, Lysiosquillina lisa Ahyong & Randall, 2001, Lysiosquillina maculata (Fabricius, 1793), Lysiosquilla scabricauda (Lamarck, 1818), Lysiosquilloides siamensis (Naiyanetr, 1980), Lysiosquillina sulcata (Manning, 1978), Lysiosquilla sulcirostris Kemp, 1911, Lysiosquilla tredecimdentata (Holthuis, 1941)); Macleay Museum, University of Sydney (MM) (Lysiosquilla capensis Hansen, 1895); Muséum National d’Histoire Naturelle, Paris (MNHN) (Lysiosquilla hoevenii Herklots, 1851, Lysiosquilla monodi Manning, 1977); Museum Zoologicum Bogoriense, Indonesia (MZB) (Lysiosquillina lisa Ahyong & Randall, 2001, Lysiosquilloides mapia Erdmann & Boyer, 2003); National Museum of Natural History, Smithsonian Institution, Washington D.C. (USNM) (Lysiosquilla campechiensis Manning, 1961, Lysiosquillina glabriuscula (Lamarck, 1818), Lysiosquilla manningi Boyko, 2000, Lysiosquilla panamica Manning, 1971); Naturalis Biodiversity Centre, Leiden (Lysiosquilloides aulacorhynchus (Cadenat, 1957)); Queensland Museum, Brisbane (QM) (Lysiosquilla suthersi Ahyong, 2001). The data matrix, constructed in MacClade 4.0 (Maddison and Maddison 2000), includes 23 terminals and 37 characters (Appendix 1). Characters were unordered (non-additive) and equally weighted, and polymorphisms were scored as such rather than assuming a plesiomorphic state. Trees were generated in PAUP 4.0b2a (Swofford 2002) under the heuristic search (MULPARS, tree-bisection-reconnection, 1000 replications with random input order). Relative stability of clades was assessed using jackknifing (30% character deletion; 1000 pseudoreplicates). Morphological characters Eyes, antennules and antennae Character 1. Cornea mesial lobe: normal (0); conical (1). The mesial lobe in stomatopods with a broadened, bilobed eye, is typically rounded and somewhat hemispherical, but in most species of Lysiosquilloides, conical and distally pointed. Character 2. Antennular somite dorsal process apices: directed anteriorly (0); directed anterolaterally (1). The apices of the antennular somite dorsal processes are directed anteriorly in the outgroups and most ingroup species, but are directed anterolaterally in Lysiosquilla isos, L. monodi and L. sulcirostris. Character 3. Antennular somite dorsal processes: low, reduced (0); prominent, well-developed (1). The dorsal processes of the antennular somite are prominent and well developed in erythrosquilloids and most lysiosquilloids, but low and reduced in Lysiosquilloides. The apices of the dorsal processes are directed anteriorly in most lysiosquilloids, anterolaterally directed in Lysiosquilla isos, L. monodi and L. sulcirostris (see Ahyong 2004). Character 4. Antennular peduncle flanges: absent (0); present (1). The antennular peduncle of species of Lysiosquilloides have lateral flange on articles 1 and 2. The flange on article 1 is prominent, with the distoand proximolateral corner almost a right-angle; that of article 2 is weakly cristate. Other lysiosquilloids lack these distinct flanges, instead having at most a narrow crista. Character 5. Antennal protopod anteromesial projection: forming a spine (0); papillate (1); a low blunt lobe (2); absent (3). The anteromesial margin of the antennal protopod is armed in most species of Lysiosquilla, unarmed in most species assigned to Lysiosquillina, and with a low blunt lobe in Lysiosquilla campechiensis, L. suthersi, and Lysiosquillina lisa. In Lysiosquilloides, anteromesial projection forms a prominent papilla. Character 6. Antennal papillae size: short, squat (0); elongated, prominent (1). The antennal papillae are slender and elongated in lysiosquillids and Acanthosquilla, short and squat in other taxa. page 3 of 14Zoological Studies 61:12 (2022) © 2022 Academia Sinica, Taiwan Character 7. Antennal mesial papilla: absent (0); present (1) (Ahyong and Harling 2000; Ahyong 2001). Character 8. Antennal scale proportions: slender, length 3.0 × width or greater (0); broad, length about 2.5 × width (1) (Manning 1995; Ahyong 2001; Ahyong and Randall 2001). Character 9. Antennal scale outline: pale (0); darkly pigmented (1) (Manning 1978; Ahyong 2001). Character 10. Antennal scale median pigment patch: absent (0); present (1) (Manning 1978; Ahyong 2001). Character 11. Ocular scales: short, blunt (0); slender, spiniform (1) (Ahyong 2001, 2004). Rostral plate Shape (Characters 12, 15, 16) and surface ornamentation (Characters 13, 14) of the rostral plate is informative for species and genera. The rostral plate is triangular or cordiform-ovate in most terminal taxa, but polygonal in Acanthosquilla. A median carina or median sulcus is usually present in lysiosquillids, but in several species, a flanking sulcus lateral to the midline may also be present. Character 12. Rostral plate general shape: triangular (0); cordiform-ovate (1); polygonal (2). Character 13. Rostral plate midline: smooth (0); carinate (1); sulcate (2). Character 14. Rostral plate surface lateral to midline: smooth (0); sulcate (1). Character 15. Rostral plate widest point: basally (0); proximally, slightly in advance of base (1); at midlength (2). Character 16. Rostral plate proximal margin: straight to slightly convex (0); concave (1). The lateral margin in the proximal half of the rostral plate is concave in Lysiosquilla campechiensis and L. suthersi, straight to convex in other terminal taxa. Thoracic somites and appendages Character 17. Thoracic sternite 8 keel shape: rounded (0); quadrate (1); triangular (2). (Ahyong 2001). Character 18. Thoracic sternite 8 apex: blunt (0); angular (1); sharply pointed (2). (Ahyong 2001). Character 19. Pereopod 1 endopod shape: ovalelongate (0); liguliform (1). (Ahyong 1997; Ahyong and Harling 2000). Character 20. Raptorial claw dactylus teeth: five (0); six (1); seven (2); eight (3); nine (4); ten or more (5). Abdominal somites and appendages Character 21. Abdominal somite 5 posterior margin spinules: absent (0); present (1). (Manning 1969, 1977). Character 22. Abdominal somite 6 dorsal surface irregular, scabrous ornamentation: absent (0); present (1). Irregular, scabrous ornamentation on abdominal somite 6 is present in several species of Lysiosquilla Character 23. Abdominal somite 6 margin and surface spinulation: absent (0); present (1). Several lysiosquillids have small spinules on the margins and surface of abdominal somite 6. Character 24. Abdominal somite 6 posterolateral spine: present (0); absent (1). The posterolateral angle of the abdominal somite 6 is unarmed in lysiosquillids, but produced to a spine in the remaining terminals. Character 25. Uropodal protopod dorsal spinules: absent (0); present (1). The dorsal surface of the uropodal protopod may be spinulose adjacent to the dorsal spine above the exopod articulation. Character 26. Uropodal protopod tubercle or spine at base of endopod articulation: present (0); absent (1). Character 27. Uropodal endopod shape: reniform (0); spatulate (1). The uropodal endopod is reniform in two outgoups (Heterosquilla and Erythrosquilla), and spatulate in other terminal taxa. Character 28. Uropodal protopod inner primary spine length: shorter than outer spine (0); longer than outer spine(1). Character 29. Uropodal protopod terminal spines shape: broad, dorsoventrally flattened (0); slender (1). The terminal spines of the uropodal protopod are dorsoventrally flattened in erythrosquilloids and many lysiosquilloids, but slender and spiniform in lysiosquillids. Telson Character 30. Telson surface: smooth (0); tuberculate, spinular (1). The dorsal surface the telson is tuberculate and minutely spinular in adults of Lysiosquilla hoevenii, L. manningi and L. scabricauda. Character 31. Telson outline in adults: polygonal (0); subrectangular (1); semi-ovate (2). The telson outline is subrectangular or semi-ovate in most ingroup species, and polygonal in Heterosquilla and the outgroup, Erythrosquilla. Character 32. Telson median boss or carina posterior spine or lobe: present (0); absent (1). page 4 of 14Zoological Studies 61:12 (2022) © 2022 Academia Sinica, Taiwan Character 33. Telson lateral margin armature: absent (0); present (1). The lateral margin of the telson is lined with short spines or serrations in adults of Lysiosquilla hoevenii and L. scabricauda. Character 34. Telson submedian teeth: movable (0); fixed (1) (Ahyong and Harling 2000). Character 35. Telson submedian denticles: present (0); absent (0) (Ahyong and Harling 2000). Character 36. Telson intermediate denticles: spiniform (0); rounded (1) (Ahyong and Harling 2000). Character 37. Telson intermediate and lateral teeth: well-developed, spiniform (0); stout, fused into telson margin (1) (Ahyong and Harling 2000). RESULTS The phylogenetic analysis resulted in a single most parsimonious cladogram (length 78, consistency index 0.6154, retention index 0.8077; Fig. 2). Unambiguous character state changes are given in table 1. Lysiosquillidae comprises two reciprocally monophyletic clades, one corresponding to Lysiosquilloides (100% jackknife support) and the other containing the remaining lysiosquilloids (94% jackknife support), comprising species assigned to Lysiosquilla and Lysiosquillina. Within Lysiosquilloides, the IndoWest Pacific species form a clade as sister to the eastern Atlantic Ls. aulacorhynchus. Lysiosquillina is monophyletic but nested within Lysiosquilla, rendering the latter paraphyletic. The three species with features that are intermediate between Lysiosquilla and Lysiosquillina, namely L. campechiensis, L. suthersi and Ln. lisa, form a grade leading to Lysiosquillina sensu stricto. The remaining species of Lysiosquilla comprised two reciprocally monophyletic clades, one containing species having a rugose, tuberculate telson surface (L. scabricauda, L. hoevenii and L. manningi) and the other containing species with a relatively smooth, nontuberculate telson surface. SYSTEMATICS Stomatopoda Lysiosquilloidea Giesbrecht, 1910 Lysiosquillidae Giesbrecht, 1910 Lysiosquilla Dana, 1852 Lysiosquilla Dana, 1852: 615. Type species Lysiosquilla inornata Dana, 1852 [a junior subjective synonym of Lysiosquilla scabricauda (Lamarck, 1818)], by subsequent designation by Fowler (1912: 539). Name on Official List of International Commission on Zoological Nomenclature. Gender feminine. Fig. 2. Phylogeny of Lysiosquillidae. Single most parsimonious cladogram, length 78, consistency index 0.6154, retention index 0.8077. Numbers on nodes indicate jackknife support values (above) and node number (below) with unambiguous character state changes listed in table 1. page 5 of 14Zoological Studies 61:12 (2022) © 2022 Academia Sinica, Taiwan Lysiosquillina Manning, 1995: 133. Type species Squilla maculata Fabricius, 1793, by original designation. Gender feminine. [New synonymy] Diagnosis: Rostral plate anteriorly smooth or with low median carina, without median sulcus. Eye large, T-shaped; cornea strongly bilobed, mesial lobe rounded. Dorsal processes of antennular somite well-developed, with anterolateral spine. Antennular peduncle article 1 weakly cristate laterally; article 2 subcylindrical. Antennal protopod mesially unarmed, with short blunt lobe or short anteromesial spine anterior to mesial papilla. Mandibular palp present or absent. Telson submedian teeth with fixed apices in adults; submedian denticles absent adults; median boss without posterior spine or lobe. Composition: Lysiosquilla campechiensis Manning, 1962; L. capensis Hansen, 1895; L. colemani Ahyong, 2001; L. glabriuscula (Lamarck, 1818); L. hoevenii (Herklots, 1851); L. isos Ahyong, 2004; L. lisa (Ahyong & Randall, 2001) comb. nov.; L. maculata (Fabricius, 1793); L. manningi Boyko, 2000; L. monodi Manning, 1977; L. panamica Manning, 1971; L. scabricauda (Lamarck, 1818); L. sulcata Manning, 1978; L. sulcirostris Kemp, 1913; L. suthersi Ahyong, 2001; and L. tredecimdentata Holthuis, 1941. Remarks: Given the synonymization of Lysiosquillina and Lysiosquilla, the two remaining genera of Lysiosquillidae are rediagnosed herein. Lysiosquilla now includes 16 species including the four species previous assigned to Lysiosquillina. Distinctions between Lysiosquilla and Lysiosquilloides are discussed in the Remarks of the latter. All species of Lysiosquilla exceed TL 100 mm in maximum size (usually > TL 150 mm), with L. maculata from the Indo-West Pacific, the largest known stomatopod, reaching TL 385 mm (Roxas and Estampador 1930). Lysiosquilloides Manning, 1977 Lysiosquilloides Manning, 1977: 84–85. Type species Lysiosquilla aulacorhynchus Cadenat, 1957, by original designation and monotypy. Gender masculine. Diagnosis: Rostral plate anteriorly with median sulcus. Eye large, T-shaped, cornea strongly bilobed, mesial lobe distinctly conical (less pronounced in Ls. siamensis). Dorsal processes of antennular somite low, blunt, without anterolateral spine. Antennular peduncle article 1 with prominent lateral crista, distoand proximolateral corner almost a right-angle; article 2 lateral margin weakly cristate. Antennal protopod margin anterior to mesial papilla with prominent, anteromesial projection, distally uncalcified, papillate, apex soft, pointed. Mandibular palp present. Telson submedian teeth with movable apices; submedian denticles present adults; median boss with posterior spine or blunt lobe. Composition: Lysiosquilloides aulacorhynchus (Cadenat, 1957); Ls. mapia Erdmann & Boyer, 2003; Ls. siamensis (Naiyanetr, 1980), Ls. taiwanica sp. nov. Remarks: Lysiosquilloides is most easily Table 1. Unambiguous character state reconstructions for single most parsimonious cladogram (length 78, consistency index 0.6154, retention index 0.8077) for nodes as indicated in figure 2 Node 1. 6: 0→1; 27: 0→1; 28: 0→1; 29: 0→1 Node 2. 7: 0→1; 19: 0→1; 24: 0→1; 36: 0→1; 37: 0→1 Node 3. 1: 0→1; 3: 1→0; 4: 0→1; 5: 0→1; 17: 0→1 Node 4. 8: 0→1; 11: 0→1; 15: 1→2 Node 5. 17: 1→2 Node 6. 32: 0→1; 34: 0→1; 35: 0→1 Node 7. 9: 0→1; 17: 0→2 Node 8. 18: 0→1; 21: 0→1; 22: 0→1; 23: 0→1; 25: 0→1; 30: 0→1; 31: 1→2 Node 9. 33: 0→1 Node 10. 19: 1→0 Node 11. 18: 0→2 Node 12. 2: 0→1 Node 13. 11: 0→1; 13: 1→0 Node 14. 12: 1→0; 14: 0→1 Node 15. 15: 1→0; 26: 0→1 Node 16. 5: 0→2 Node 17. 15: 1→2; 16: 0→1; 20: 5→2 Node 18. 10: 0→1 Node 19. 5: 2→3 Node 20. 20: 5→2 page 6 of 14Zoological Studies 61:12 (2022) © 2022 Academia Sinica, Taiwan distinguished from Lysiosquilla by the movable (versus fixed) submedian teeth on the telson, presence of submedian denticles in adults, conical mesial lobe of the cornea (most prominent in Ls. mapia and Ls. taiwanica), the median boss of the telson having a short posterior spine or lobe (unarmed in Lysiosquilla), the low, unarmed dorsal processes of the antennular somite and the large, papillate dorsomesial projection on the antennal protopod. A new distinguishing feature of Lysiosquilloides identified here is in the ornamentation of the lateral margin of antennular peduncle articles 1–2: a distinct lateral crista on article 1 and weakly cristate margin on article 2. In Lysiosquilla, antennular peduncle article 1 is weakly cristate, and article 2 is subcylindrical and smooth, without a lateral crista. In parallel with Lysiosquilla as revised herein, Lysiosquilloides includes species with slender through broad antennal scales. The antennal scale is most slender in Ls. aulacorhynchus (length 2.9–3.1 × width), broadest in Ls. mapia and Ls. taiwanica sp. nov. (~2.5) and somewhat intermediate in Ls. siamensis (2.4–2.7) (Manning 1977; Ahyong 2001; Erdmann and Boyer 2003). Lysiosquilloides taiwanica sp. nov. (Figs. 3, 4) urn:lsid:zoobank.org:act:45635710-340F-4D12-81A0744D19B07241 Type material: NMMBA CD5609, male holotype (TL 145 mm), Hojie, Pingtung County, Taiwan, 26–28 m, from burrow in sandy bottom close to coral reef, coll. C.-W. Lin, 18 February 2017. Diagnosis: Cornea mesial lobe distinctly conical, apex bluntly pointed. Antennal scale broad, length 2.50 × width. Rostral plate ovate, slightly longer than wide, widest at midlength; apex deflexed; with short median sulcus anteriorly. Raptorial claw dactylus with 7 teeth. Thoracic somite 8 sternal keel blunt, angular. Telson length 0.70 × width; with median boss terminating in small spine. Uropodal protopod with small ventral spine anterior to endopod articulation; endopod extending posteriorly slightly beyond telson posterior margin. Description: Eye large, cornea set slightly obliquely on stalk, extending to end of antennular peduncle article 2 (Fig. 3A); cornea mesial lobe distinctly conical, apex bluntly pointed; CI 347. Ophthalmic somite anterior margin obtusely angular, unarmed; ventral margin with bluntly rounded median keel (Fig. 3D). Ocular scales produced as slender spines, directed anterodorsally (Fig. 3C). Antennular peduncle length 0.46CL; articles 1–2 lateral margin with straight, narrow crista, widest on article 1 (Fig. 3E). Antennular somite dorsal processes low, broad, subquadrate, apices short, acute directed anteriorly (Fig. 3A). Antennal protopod with 1 mesial and 2 ventral papillae; anteromesial margin with prominent, elongate lobe, basally sclerotised, distally papilliform, larger and longer than mesial papilla, apex inclined anteriorly (Fig. 3A, F). Antennal scale length 2.50 × width; 0.51CL; entire margin setose (Fig. 3A). Rostral plate ovate; slightly longer than wide; widest at midlength; margins convex, almost straight in proximal one-third; apex slightly deflexed, rounded; dorsal surface with median sulcus anteriorly; ventral surface smooth (Fig. 3A, B). Carapace anterolateral angles rounded; posterior margin concave. Raptorial claw (Fig. 3G) dactylus with 7 graded teeth, outer margin broadly convex along distal half, almost straight along proximal half, with shallow basal notch. Propodus longer than carapace, distal margin unarmed; occlusal margin pectinate, with 4 movable spines proximally; PI 73. Carpus dorsal margin terminating in short stout spine, directed ventrally when claw folded. Merus unarmed. Ischium length one-third merus length. Mandibular palp 3-segmented. Maxilliped 5 basal segment unarmed; merus with broad flange on inner margin, distally truncate (Fig. 3H). Maxilliped 1–5 each with epipod. Thoracic somite 5 lateral process obsolete. Thoracic somites 6–8 lateral process broadly rounded (Fig. 3I). Thoracic somite 8 sternal keel angular, blunt (Fig. 3J). Pereopods 1–3 proximal article unarmed; endopod slender, flattened, liguliform (Fig. 3K–M). Pleopod 1 endopod without posterior ‘endite’ (Fig. 3Q). Abdominal somites 1–5 with rounded posterolateral angles. Somite 5 smooth medially and laterally; posterior margin unarmed. Abdominal somite 6 (Fig. 3N) smooth medially; with low, smooth lateral boss flanked mesially by shallow groove; with acute, triangular ventrolateral projection anterior to uropodal articulation; sternum posterior margin unarmed. Telson (Fig. 3N) subquadrate, wider than long, length 0.70 × width; surface smooth, with few, broad, shallow pits flanking low median and submedian bosses; median boss posterior spine well developed, slightly overreaching posterior telson margin (Fig. 3O); margin carina distinct; lateral margins weakly convex, unarmed; articulated submedian teeth slender, conical; 13–16 submedian denticles either side of midline; intermediate and lateral teeth short, slender; intermediate and lateral denticles rounded, each with minute spiniform apex; ventral surface unarmed. Uropodal protopod (Fig. 3N, P) unarmed dorsally page 7 of 14 Zoological Studies 61:12 (2022) © 2022 Academia Sinica, Taiwan Fig. 3. Lysiosquilloides taiwanica sp. nov., male holotype, TL 145 mm, Hojie, Taiwan, NMMBA CD5609: A, anterior cephalothorax, dorsal view; B, rostral plate, dorsal view; C, ocular scales, dorsal view; D, ophthalmic somite ventral keel, right lateral view; E, right antennular peduncle, dorsal view; F, right antenna, lateral view; G, right raptorial claw, lateral view; H, right maxilliped 5 merus; I, right thoracic somites 6–8, dorsal view; J, thoracic somite 8 sternal keel, right lateral view; K–M, right pereopods 1–3, posterior view; N, posterior abdomen and right uropod, dorsal view; O, posterior telson, right lateral view; P, right uropod, ventral view; Q, right pleopod 1 endopod, anterior view. Scale: A, D–P = 5 mm; B, C, Q = 2.5 mm. page 8 of 14 Zoological Studies 61:12 (2022) © 2022 Academia Sinica, Taiwan except for spine above proximal exopod articulation; with small ventral spine anterior to endopod articulation. Uropodal exopod proximal segment unarmed dorsally; inner distal margin with broad, round lobe; outer margin with 7 movable, distally flattened spines, distalmost spine reaching midlength of distal segment; distal margin with stout ventral spine. Exopod distal segment ovate, length twice width, longer than proximal segment, with dorsal and ventral median carina. Endopod elongate, length 2.45 × width, extending posteriorly slightly beyond telson posterior margin. Colour in life: (Fig. 4). Carapace and antennal scale transversely banded with pale cream-yellow and dark maroon; maroon bands diffuse, mottled, on anterior Fig. 4. Lysiosquilloides taiwanica sp. nov., male holotype, TL 145 mm (left raptorial claw missing), Hojie, Taiwan, NMMBA CD5609, colour in life. A, dorsal habitus; B, in habitat. page 9 of 14Zoological Studies 61:12 (2022)