Lepidophthalmus Holmes, 1904

Poore, Gary C. B., Dworschak, Peter C., Robles, Rafael, Mantelatto, Fernando L. & Felder, Darryl L., 2019, A new classification of Callianassidae and related families (Crustacea: Decapoda: Axiidea) derived from a molecular phylogeny with morphological support, Memoirs of Museum Victoria (Mem. Mus. Vic.) 78, pp. 73-146 : 112

Lepidophthalmus Holmes, 1904

Lepidophthalmus Holmes, 1904: 310 .— Manning and Felder, 1991: 778–779.— Sakai, 1999a: 64–65.— Sakai and Apel, 2002: 278.— Sakai, 2005b: 143–144.— Felder, 2001: 440.— Sakai, 2011: 446.— Robles and Felder, 2015: 462–464 , 467–468, fig. 1.— Komai et al., 2018: 23–24.

Podocallichirus Sakai, 1999a: 53–54 .— Sakai, 2005b: 187–189 (partim).— Sakai, 2011: 466–467.— Hyžný and Muñiz, 2012: 619– 621.— Hyžný and Karasawa, 2012: 62–63.— Hyžný, 2016: 44–45.— Komai et al., 2018: 24 (type species: Callianassa madagassa Lenz and Richters, 1881 , by original designation and monotypy) syn. nov.

Lepidophthalmoides Sakai, 2011: 440–441 (type species: Lepidophthalmus eiseni Holmes, 1904 , by original designation) objective synonym.

Lepidophthalminus Sakai, 2015: 433 (replacement name for Lepidophthalmus sensu Sakai, 2011 ; type species, Callianassa bocourti A. Milne-Edwards, 1870 , by original designation) syn. nov.

Type species. Lepidophthalmus eiseni Holmes, 1904 , by monotypy.

Diagnosis. Anterior branchiostegal lobe sclerotised, well produced anteriorly beyond junction with oblique branchiostegal ridge which it meets level with linea thalassinica. Rostrum spine-like; anterolateral angles obsolete or spinous. Pleomere 1 tergite undivided or with weak transverse step. Antennular peduncle length less than 3 times as width of both eyestalks or more than 3 times the width of both eyestalks (rare), longer than antennal peduncle. Maxilliped 3 ischium and merus narrow, more than twice as long as wide at their articulation, or rarely less than twice as long as wide at their articulation; crista dentata absent (or few proximal spines only); propodus about as wide as long, free distal margin clearly oblique, or free distal margin transverse or nearly so; dactylus curved, 3 times as long as wide, concave below; exopod present. Male major cheliped merus with sinuous lower margin, widest proximally and excavate beyond, or with proximal tubercle bearing spine(s) with or without more distal teeth along lower margin; dactylus typically tapering, or massive, upper margin expanded, strongly convex, dentate. Male minor cheliped half or more as wide as major, carpus as long as or shorter than palm, fingers as long as or longer than palm. Pereopod 3 propodus subpentagonal, with strong broadly rounded proximal lobe on lower margin, lower margin straight-concave, lower margin with broad deep notch between distal lobe and heel. Pereopod 4 subchelate. Male pleopod 1 consisting of 2 articles, article 2 tapering, with small acute subdistal lobe, acute distal apex. Male pleopod 2 appendix interna absent, or reduced to obsolete distomesial lobe, or apparent only as field of hooks on side of appendix masculina. Pleopods 3–5 appendices internae barely emerging from endopod margin. Uropodal endopod with convex anterior margin, acute-rounded apex, straight-slightly curved posterior margin, longer than wide. Telson with convex lateral margins and rounded posterolateral corners, posterior margin trilobed, excavate each side of medial lobe, or convex, with medial lobe.

Remarks. Lepidophthalmus differs from other callichirids in the combination of short antennal peduncle, telson with convex lateral margins and quasi-trilobed posterior margin, a series of concavities along the lower margin of the propodus of pereopod 3, and a curved narrow dactylus on maxilliped 3. Some species have particularly setose fingers on the minor cheliped or with long setae on the mesial face of the major cheliped extending into the gape between the fingers. Lepidophthalmus shares an exopod on maxilliped 3 with Karumballichirus , Kraussillichirus and Glypturoides .

Sakai (2011) placed eight species in his new genus Lepidophthalmoides Sakai, 2011 , an objective synonym of Lepidophthalmus Holmes, 1904 . Both have the same type species. Sakai (2015) realised the error and erected Lepidophthalminus Sakai, 2015 , to replace Lepidophthalmus sensu Sakai, 2011 , this time with Callianassa bocourti A. Milne-Edwards, 1870 , as type species, with only five included species and referring to his 2011 diagnosis of Lepidophthalmus to differentiate it from Lepidophthalmus Holmes, 1904 . Sakai (2011) separated the two “genera” in the male pleopod 1 being “chelate” in the former and simple in the latter. Incidentally, the adjective “chelate” is inappropriate in this context—the second article has a mesiodistal notch, not formed by two distal opposing articles. A review of all 15 known species reveals that one pleopod form grades into the other and may reflect developmental stages. Komai et al. (2018) has already pointed out that the generic division of Sakai (2015) has no merit. Lepidophthalminus isheresynonymisedwith Lepidophthalmus .

No consistent morphological difference was found between American and Indo-West Pacific species ( Komai et al., 2018; Robles et al., in press; Robles and Felder, 2015). Most species of Lepidophthalmus are found in estuarine habitats where their ecology has been studied ( Felder, 2001; Filho et al., 2013; Hernáez et al., 2012).