Caviallianassa moorea Poore, 2023, sp. nov.
Creators: name: Poore, Gary C. B.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Callianassidae
Caviallianassa
Caviallianassa moorea

description: Caviallianassa moorea sp. nov.   
http://zoobank.org/urn:lsid:zoobank.org:act:979A1ED7-4734-  
428B-A119-A6754443E6DF  
Figures 1b, 10–12  
 Caviallianassa FP-11.— Poore et al., 2019: figs 3h, 6c, 8g, 10e, f, 11b, c.— Robles et al., 2020: figs 1, 3, 6.   
 Caviallianassa PNG-1165.— Robles et al., 2020: figs 1, 3, 6.   
 Material examined. Holotype. French Polynesia, Moorea, between Cook’s Bay and Hilton, off Pihaena, 17.481° S, 149.8300° W (stn BIZ-632), UF 29204 (ovigerous female, 3.9 mm). Paratypes. Moorea, near Nihimaru river estuary, 17.535° S, 149.906° W (stn MB-216), UF 16481 (male, 3.0 mm), UF 16467 *# (ovigerous female, 3.1 mm). Papetoai, 17.49° S, 149.88° W, 0–3 m: stn BIZ-493, UF 28909 * (ovigerous female, 2.6 mm); stn BIZ-463, UF 28819 * (ovigerous female, 2.9 mm); stn BIZ-539, UF 28875 * (ovigerous female, 3.8 mm); stn BIZ-493, UF 28904 * (ovigerous female, 3.6 mm); stn BIZ-109, UF 23873 # (ovigerous female, 3.8 mm); stn BIZ-109), UF 29097 # (ovigerous female, 3.8 mm). Other material. Papua New Guinea, Madang, near Rempi Mission, 5° 1.6' S, 145° 47.9' E, 2–15 m (PAPUA NIUGINI stn PR76), MNHN IU-2013-7092 *# (ovigerous female, 4.0 mm).   
 Description. Female. Rostrum triangular, blunt, flat, situated level with dorsal carapace, much shorter than eyestalks. Carapace dorsally flat, three quarters length of pleomeres 1, 2 combined; orbital margin almost transverse; anterolateral angle obtuse; subanterolateral margin weakly concave; anterior margin of branchiostegite with dorsal concavity; cervical groove deeply incised, across 0.8 length of carapace, reaching linea thalassinica. Pleomere 1 tergite with transverse groove, posterior half much wider than anterior half. Pleomere 2 1.1 times as long as wide. Pleomeres 3–5 each wider than long; pleura each with patch of plumose setae. Pleomere 6 about as long as wide, 1.1 times as long as pleomere 5, with obscure posterolateral groove.   
Eyestalk about 2.5 times as long as wide, not concealed by rostrum, with lateral margin convex in dorsal view, anteromedial angle angular in dorsal view, reaching distal margin of antennular peduncle article 1. Cornea densely pigmented, occupying anterolateral-dorsal margin of eyestalk.  
Antennular peduncle reaching beyond distal margin of antennal peduncle; article 1 not visible in dorsal view; article 3 about as long as articles 1 and 2 combined; articles 2 and 3 with longitudinal ventral row of long setae. Antennal peduncle article 5 0.8 times as long as article 4, reaching 0.7 length of antennal article 3; scaphocerite minute, oval.  
Mandible molar process shelf-like, with small mesial teeth; incisor process with irregular teeth. Maxilliped 3 ischium dilating distally, 1.5 times as wide as long, crista dentata consisting of row of about 15 small, well-spaced sharp teeth; merus shorter than ischium, about twice as wide as long, with mesiodistal margin produced as convex lobe beyond base of carpus; carpus 0.7 times merus outer margin; propodus subrectangular, 1.2 times as long as wide; dactylus as long as propodus, with convex extensor (outer) margin, densely setose distally, with straight flexor (inner) margin bearing 3 or 4 setae.  
Pereopods 1 (chelipeds) unequal, dissimilar. Female major cheliped massive, carpus-palm upper margin just exceeding carapace length. Ischium expanding distally, upper margin concave, unarmed; lower margin with 4 obsolete teeth. Merus as long as ischium, twice as long as wide, subrectangular; upper margin convex, unarmed; lower margin with 3 small subproximal teeth, with denticulate blade over third quarter. Carpus about as long as wide; margins carinate; upper margin smooth; lower margin convex. Propodus upper margin as long as carpus; palm of almost even width, 1.1 times as long as wide; upper margin carinate; lateral surface smooth, convex, with 4 clusters of long setae in gape; mesial surface slightly convex, with 2 denticles and 1 cluster of long setae at base of finger; lower margin carinate, with row of clusters of setae extending onto fixed finger; fixed finger 0.67 times as long as palm, not depressed, base 0.6 times length; cutting edge with finely denticulate blade along lateral margin. Dactylus overreaching fixed finger, with acute tip; upper margin with tufts of long setae; cutting edge finely denticulate over distal three quarters.  
Minor cheliped carpus-palm upper margin 0.9 carapace length. Ischium margins smooth. Merus about as long as ischium; lower margin convex distally, unarmed. Carpus widest over distal half, 1.25 times as long as merus, twice as long as wide. Palm 1.25 times as long as wide; upper margin barely convex; lower margin sharply carinate, with row of long setae extending onto fixed finger; lateral face with cluster of long setae at base of finger. Fixed finger deep, triangular, 0.7 length of palm, cutting edge denticulate except over distal third. Dactylus longer than palm, curved; cutting edge smooth.  
Pereopod 2 merus lower margin slightly sinusoidal, twice as long as wide; carpus about 1.8 times as long as wide; chela subtriangular; palm about twice as wide as upper margin; dactylus 2.3 times as long as palm upper margin. Pereopod 3 carpus subtriangular, 1.7 times as long as wide; propodus subrectangular with broadly produced lower proximal margin, upper margin equal to greatest width, lower margin almost straight, with short subdistal spiniform seta; dactylus about as long as propodus upper margin. Pereopod 4 coxa flattened ventrally, immovable; merus 1.5 times as long as ischium; carpus 0.9 length of merus; propodus 0.8 length of carpus, with dense grooming setae distally on lower margin, scattered stiff setae on outer surface, with long spiniform setae parallel to dactylus; dactylus half as long as propodus.  
Female pleopod 1 of 2 articles at right angles; peduncle with strong bend; ramus half as long as peduncle. Female pleopod 2 biramous; peduncle bent; exopod 0.7 length of endopod; endopod of 2 articles, second two-thirds length of first. Pleopods 3–5 biramous, rami narrow; appendix interna projecting well beyond mesial margin of endopod, bearing coupling hooks on apical margin.  
Uropod endopod and exopod overreaching posterior margin of telson. Endopod oval, widest near midpoint, about 1.3 times as long as wide; upper surface with 1 proximal spiniform seta; anterior margin straight; distal margin broadly convex, with fringe of setae; posterior margin setose. Exopod widest at midpoint, about as wide as long; anterior margin straight; posterior margin semicircular, with numerous slender setae, with more than 20 blade-like setae indistinguishably merged with distal margin; upper surface without setae; dorsal plate extending about one third across exopod, with row of numerous stiff setae merging anteriorly with similar setae on distal margin.  
Telson 1.4 times as wide as long, broadest at anterior third, with lateral and posterior margins continuous; posterior margin concave, with 2 sublateral pairs of spiniform setae, with median tooth.  
 Male. Major cheliped similar to that of female. Ischium lower margin with 6 irregular teeth. Merus lower margin with 3 subproximal teeth, with denticulate blade over third quarter. Propodus upper margin 1.15 times as long as carpus; palm of almost even width, 1.15 times as long as wide; lateral surface with 2 clusters of long setae in gape; mesial surface with 1 denticle and 1 cluster of long setae at base of finger; fixed finger 0.67 times as long as palm, not depressed, base half length; cutting edge mostly smooth.   
Pleopod 1 of 2 articles; peduncle curved; ramus twisted, 0.4 length of peduncle. Pleopod 2 biramous; peduncle bent; exopod slightly shorter than endopod; endopod of 2 articles, second third length of first.  
 Etymology. From Moorea, where the type specimen was collected (noun in apposition).   
 Distribution. Southeast Polynesia, Eastern Coral Triangle (French Polynesia, Papua New Guinea); intertidal.   
 Remarks. Robles et al. (2020) found almost no genetic differences between four specimens of “ C. FP-11” from Moorea in their molecular phylogram. Another, “ C. PNG-1165” from Papua New Guinea was sister of these but more remote (0.036 divergence for the 12S gene) and may warrant recognition as a separate species. No meaningful morphological differences in the telson, uropod or antennae were detected between this ovigerous female (MNHN IU- 2013-7092) and those from Moorea. The major cheliped (fig. 12e) is slightly more slender; the merus has one tooth rather than two or three but has the same tubercle in the gape. The cheliped, and other features, differ significantly from the only specimen of Caviallianassa from Papua New Guinea described below as another species.
description: Published as part of Poore, Gary C. B., 2023, New records, one new genus and 21 new species of Callianassidae (Crustacea, Axiidea) from the Indo-West Pacific, pp. 167-255 in Memoirs of Museum Victoria 82 on pages 181-185, DOI: 10.24199/j.mmv.2023.82.09, http://zenodo.org/record/12214445