Rudisullianassa pandan, Poore, 2023

Poore, Gary C. B., 2023, New records, one new genus and 21 new species of Callianassidae (Crustacea, Axiidea) from the Indo-West Pacific, Memoirs of Museum Victoria 82, pp. 167-255 : 236-238

Rudisullianassa pandan sp. nov.

http://zoobank.org/urn:lsid:zoobank.org:act:39DA749A-D7B1-

4A40-A246-34F1BA361BC4

Figures 1h , 47

Rudisullianassa PNG-369.— Robles et al., 2020: figs 1, 3, 6.

Material examined. Holotype. Papua New Guinea, Madang Province, S of Tab I., 05° 10.3' S, 145° 50.3' E, 2–4 m, associated with Pandanus wood ( PAPUA NIUGINI stn PR22 ), MNHN IU-2013-7054 * (female, 4.2 mm) . Paratypes. Collected with holotype, MNHN IU-2013-7063 *# (female without pleon, 4.5 mm), MNHN IU-2013-437 (ovigerous female, 3.52 mm), MNHN IU-2017-1347 (10 hermaphrodites, 3–4 mm), MNHN IU-2017-1348 *# (hermaphrodite, 4.7 mm), MNHN IU-2017- 1349 (ovigerous female, 3.6 mm), MNHN IU-2017-1350 (ovigerous female, 3.5 mm), NMV J71657 (2 hermaphrodites, 3.5, 3.9 mm) . Other material. Papua New Guinea, Madang Province, ( PAPUA NIUGINI stn PR58 ), MNHN IU-2013-7132 (female, 4.3 mm) .

Description. Rostrum barely projecting, situated level with dorsal carapace, as long as eyestalks. Carapace dorsally flat, as long as pleomeres 1 and 2 and half of pleomere 3 combined; orbital margin transverse; anterolateral angle not projecting, obtuse; subanterolateral margin oblique, anterior margin of branchiostegite with dorsal lobe; cervical groove across 0.85 length of carapace, reaching linea thalassinica, scarcely incised in lateral view. Thoracic sternite 7 subpentagonal with projecting anteromedian margin; ventral surface without median groove; posterior margin with negligible median indentation. Pleomere 1 tergite narrowest anteriorly. Pleomere 2 slightly wider than long. 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 obsolete ventrolateral groove.

Eyestalk 1.3 times as long as wide, tapering, with gently sloping anterior face, anteromesial angle rounded in dorsal view, reaching distal margin of antennular peduncle article 1. Cornea occupying anterolateral margin of eyestalk, darkly pigmented.

Antennular peduncle almost reaching distal margin of antennal peduncle article 5; article 1 scarcely visible in dorsal view; article 2 shorter than article 1; article 3 1.5 times as long as articles 1 and 2 combined; articles 2 and 3 with longitudinal ventral row of sparse long setae. Antennal peduncle article 5 0.8 length of article 4; scaphocerite minute, oval.

Maxilliped 3 ischium distally expanded, about as long as wide, crista dentata consisting of row of 20 small similar teeth; merus about 0.6 length of ischium measured along outer margin, about twice as wide as long, with mesiodistal lobe overreaching articulation of carpus; carpus shorter than merus; propodus oval, 1.4 times as long as wide; dactylus ovoid, 0.9 length of propodus, twice as long as wide, with dense setae over distal margins.

Pereopods 1 (chelipeds) unequal, dissimilar. Major cheliped massive, carpus-palm upper margin 1.4 times carapace length. Ischium expanding distally, upper margin concave, unarmed; lower margin with obsolete teeth. Merus 1.2 times as long as ischium, 1.6 times as long as wide, vaseshaped; upper margin convex, unarmed; lower margin with oblique distal lobe, armed with few small teeth. Carpus 1.7 times as wide as long; margins carinate, folding mesially. Propodus upper margin 2.8 times as long as carpus; palm of almost even width, 1.45 times as long as wide; upper margin with slight mesial carina; lateral surface smooth, convex, distal margin with 2 blunt rounded teeth at base of finger; mesial surface convex, with small tooth at base of finger; lower margin carinate, with row of clusters of setae extending onto fixed finger; fixed finger about half as long as palm, convex, depressed and angled mesially beyond palm; cutting edge lateral, uneven. Dactylus not overreaching fixed finger; upper margin with tufts of long setae; cutting edge with triangular blunt proximal tooth, irregularly tooth blade over distal third, with blunt hooked tip.

Minor cheliped carpus-palm upper margin about as long as that of major cheliped. Ischium margins smooth. Merus 0.75 times as long as ischium; lower margin convex with small tooth about two thirds along. Carpus widest over distal half, almost as long as merus, 1.2 times as long as wide. Palm 1.5 times as long as wide; upper margin barely convex; lower margin sharply carinate, with row of long setae extending onto fixed finger; lateral face smooth. Fixed finger 0.7 length of palm, cutting edge denticulate. Dactylus 0.74 length of fixed finger; cutting edge smooth.

Pereopod 2 merus with convex margins, 2.2 times as long as wide; carpus subtriangular, twice as long as wide; palm 1.3 times as wide as upper margin; dactylus 1.7 times as long as palm upper margin. Pereopod 3 carpus subtriangular, twice as long as wide; propodus widest proximally, tapering, without produced lower proximal margin, upper margin 1.4 times width, lower margin convex, with 1 slender subdistal spiniform seta, with evenly spaced marginal setae; dactylus nearly straight, about 0.6 length of propodus upper margin. Pereopod 4 coxa flattened ventrally, immovable; merus 1.4 times as long as ischium; carpus 0.8 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 straight, half as long as propodus. Pereopod 5 slender, subchelate.

Female pleopod 1 of 2 articles, second weakly curved. Female pleopod 2 biramous; peduncle almost straight; endopod tapering distally, slightly shorter and broader than exopod, of 2 articles. Pleopods 3–5 biramous, rami narrow; appendix interna slender, rod-like, projecting well beyond mesial margin of endopod, bearing coupling hooks on apical margin.

Uropod endopod and exopod overreaching posterior margin of telson. Endopod oval, about 1.65 times as long as wide; upper surface with 2 spiniform setae; anterior margin slightly convex; posterodistal margin convex, with fringe of setae. Exopod oval, 1.6 times as long as wide, exceeding endopod by about one third length; anterior margin convex, with 4 submarginal slender setae; posterior margin with numerous slender setae, with about 7 blade-like distal setae, indistinguishably merged with distal margin; upper surface with 1 spiniform seta; dorsal plate short, with row of about 10 stiff setae separate from setal row of distal margin.

Telson 1.2 times as long as wide, broadest at anterior fifth, narrowing posteriorly to oblique posterolateral angles, each with 2 small spiniform setae; posterior margin weakly concave; dorsal surface with few medial setae anterior to midlength.

Etymology. Pandan, a Malay word from which the palm genus Pandanus is derived (noun in apposition).

Distribution. Eastern Coral Triangle ( Papua New Guinea); 2–4 m, associated with submerged wood.

Remarks. Rudisullianassa pandan differs from R. rudisulcus in having (1) narrower uropodal rami; (2) relatively shorter telson; (3) the tooth on the distolateral margin of the palm of the major cheliped less prominently triangular; (4) the distal margin of the merus of maxilliped 3 not as produced and the dactylus not as densely distally setose; and (5) the propodus of pereopod 3 more symmetrical (it is wider proximally in R. rudisulcus ).

Both species occur in Madang Province, Papua New Guinea, and were taken from a single sample associated with submerged pandanus wood.

Figures

Figure 1. Dactylus of maxilliped 3 of representatives of two callianassoid families. Eucalliacidae. a, Calliaxina kensleyi (Dworschak, 2005), MNHN IU-2016-8084. Callianassidae. b, Caviallianassa moorea sp. nov., UF 28875; c, Paratrypaea sp, MNHN IU-2013-7035; d, Praedatrypaea lobetobensis sp. nov., MNHN IU-2015-109; e, Praedatrypaea orientalis (Bate, 1888), AM P.74473; f, Rayllianassa amboinensis (De Man, 1888), UF 8700; g, Rayllianassa bifida sp. nov., MNHN IU-2013-7137; h, Rudisullianassa pandan sp. nov., MNHN IU-2013-7063; i, Rudisullianassa rudisulcus Komai, Fujita and Maenosono, 2014, MNHN IU-2013-7121; j, Scallasis amboinae Bate, 1888, MNHN IU-2013-12303; k, Spinicallianassa spinicauda (Komai, Maenosono and Fujita, 2014), MNHN IU-2014-2778; l, Spinicallianassa papetoai sp. nov., UF 29280.

Figure 47. Rudisullianassa pandan sp. nov. Papua New Guinea. MNHN IU-2013-7054, female, 4.2 mm: a, eyestalks, carapace, pleon, telson, uropod; b, eyestalk, carapace (lateral); c, d, antennular peduncle, antennal peduncle, eyestalk, anterior carapace (dorsal, lateral); e, telson, right uropod; f, thoracic sternites 7, 8, pereopodal coxae 3–5 (gonopores shaded); g, pleomere 6 (left lateral); h, major cheliped (right, mesial); i, major cheliped distal palm, fingers (lateral); j, carpus–dactylus (upper); k, minor cheliped (left, mesial); l, maxilliped 3 (with detail of dactylus); m–o, pereopods 2–4; p–r, pleopods 1–3. Scale bars = 1 mm.