Gibbularctus gibberosus (De Man, 1905) Holthuis, 2002

Holthuis, Lipke B., 2002, The Indo-Pacific scyllarine lobsters (Crustacea, Decapoda, Scyllaridae), Zoosystema 24 (3), pp. 499-683 : 624-629

DIAGNOSIS.— The midline of the carapace has rostral pregastric, gastric and cardiac teeth. Abdomen without medio-dorsal carina. Dorsal margin of abdominal somite IV more convex than that of either somites II or III. Abdominal terga II to V with arborescent mark- ings of very narrow grooves. Abdominal pleura with bluntly rounded top directed down. Fourth antennal segment with a curved row of tubercles in the outer half of the dorsal surface outside the main oblique cari- na. Anterior margin of thoracic sternum simply V-shaped, without submedian tubercles. Sternum without distinct median tubercles, its posterior margin entire. None of the legs with a ventral hairy fringe. Gibbularctus gibberosus

( De Man, 1905) n.comb.

( Fig. 69C, D )

Arctus gibberosus De Man, 1905 [August]: 588.

Scyllarus gibberosus – De Man 1916: 64, 68, 70, 90, pl. 3 fig. 14. — Estampador 1937: 496; 1959: 41. — Holthuis 1968: 288.— McNeill 1968: 25.— Burukovsky 1974: 107; 1983: 150.— Phillips et al. 1980: 70.— Vine 1986: 107.— McWilliam et al. 1995: 564. Scyllarus Gundlachii – Paulson 1875: 96, pl. 12 fig. 5, 5a; 1961: 102, pl. 12 fig. 5 [non Scyllarus gundlachi von Martens, 1872]. Scyllarus sordidus Nobili, 1905b [30 May]: 160 [non Scyllarus sordidus Stimpson, 1858 ]. Arctus Nobilii De Man, 1905 [August]: 589. Scyllarus Paulsoni Nobili, 1906b [30 January]: 395; 1906c: 88.— De Man 1916: 65, 68, 71.

Scyllarus Nobilii – Nobili 1906a [30 April]: 56, pl. 4 fig. 15.— Bouvier 1914: 704; 1915: 188.— De Man 1916: 65, 68, 70. Scyllarus nitidus Nobili, 1906a [30 April]: 59, pl. 6 fig.27. Scyllarus paulsoni – Prasad & Tampi 1969: 84.— Phillips et al. 1980: 70. Scyllarus nobilii – Prasad & Tampi 1969: 82.— C. Michel 1974: 256.— Phillips et al. 1980: 70.

TYPE MATERIAL.— Syntypes: 1, Siboga Expedition , stn 99 ( ZMA); 1, Siboga Expedition , stn 164 ( ZMA). TYPE LOCALITY.— Philippines, off North Ubian, 6°7.5’N, 120°26’E, 16-23 m; Indonesia, NE of Misool, 1°42.5’S, 130°47.5’E, 32 m. M ATERIAL EXAMINED.— Persian Gulf. Persian Gulf, 1900, F. W. Townsend leg., 1 8 mm (BM 1900.5.7 -2). — Mission J. Bonnier and Ch. Pérez, stn, XLVII, off Dubai, Arabia, 25°10’N, 55°10’E and 24°55’N, 54°40’E, 18-27 m, pearl oyster bank, 1901, 2 ov. syntypes of Arctus nobilii De Man, 1905 and also syntypes of Scyllarus sordidus Nobili, 1905 , and S. nitidus Nobili, 1906 ( MNHN).

Seychelles. Tyro Expedition , stn 719, E of Bird Id, 3°44’S, 55°14’E, rectangular dredge, 45 m, sandy bottom, 20.XII.1992, 1 6 mm, 1 14 mm ( RMNH D 49574). — Stn 778, West of Poivre Atoll, 5°46’S, 53°11’E, 3.5 m, Agassiz trawl, 57 m, soft bottom, 1.I.1993, 1 13 mm ( RMNH D 49575).

REVES 2, stn 7, 4°52.8’S, 56°01.4’E, dredge, 57 m, hard coralligenous bottom, 3.IX.1980, 1 juv. 4 mm (MNHN-Pa 1908). — Stn 27, 4°57.8’S, 54°59.2’E, dredge, 52 m, coral bottom, 8.IX.1980, 1 10 mm (MNHN-Pa 1858). — Stn 38, 5°02.6’S, 56°49’E, dredge, 44 m, bottom with hard rocks, 13.IX.1980, 1 ov. 15 mm (MNHN-Pa 1857).

Madagascar. Madagascar without more data, 1, preserved dry ( MG). — Nosy Bé, NW coast, 1

9 mm (MNHN-Pa 588). — Banc de Pracel, West coast, trawl, 55 m, bottom sand, VI.1954, A. Crosnier leg., 1 6 mm, 1 10 mm (MNHN-Pa 301).

Japan. Okinawa, Horseshoe Cliffs, 1 km WNW Onna village, 26°30.0’N, 127°50.9’E, diving, 12 m deep, 28.VIII.1981, R. F. Bolland leg., No. 903, 1 ov.

11 mm ( USNM).

Burma. Gulf of Martaban, E. W. Oates leg., 1

9 mm (BM 88.34).

Philippines. Siboga Expedition , stn 99, off N Ubian, 6°7.5’N, 120°26’E, 16-23 m, Lithothamnion bottom, 28-30.VI.1899, 1 syntype of Arctus gibberosus De Man, 1905 ( ZMA).

RV Albatross, stn D 5165, Observation Id, N 70°W 6.40 miles, 4°58’20”N, 119°50’30”E, 16 or 33 m, coral or green mud, 24.II.1908, 1 8 mm, 2

10 mm (1 ov.) ( USNM). — Stn D 5596, Sulu Archipelago, Zamboanga Light, N 31°W, 0.1 mile, 6°54’N, 122°04’30”E, 16 m, 10.X.1909, 1 9 mm ( USNM).

FV Pele , W of Malanipa Id, Basilan Strait, 12.II.1964, B. R. Wilson leg., 1 10 mm ( WAM 356-64). — One mile + 237° from Tangalan Id in Maluso Bay, Basilan Id, 15.II.1964, B. R. Wilson leg., 1 13 mm ( WAM 355-64).

Indonesia. Siboga Expedition , stn 164, NE of Misool, 1°42.5’S, 130°47.5’E, 32 m, bottom sand, small stones and shells, 20.VIII.1899, 1 syntype of Arctus gibberosus De Man, 1905 ( ZMA).

Australia. Queensland. Great Barrier Reef Expedition, stn XVII, about 0.25 mile N of N Direction Id, off Lookout Point near Cape Flattery, dredge, 35 m, 9.III.1929, 1 14 mm ( BM).

Chesterfield Islands. CORAIL 2, stn DW 122, 19°28.17’S, 158°17.86’E, 32 m, 29.VIII.1988, 1

8 mm, 1 9 mm (MNHN-Pa 1285). — Stn DW 146, 19°37.0’S, 158°16.28’E, 44 m, 30.VIII.1988, 1 7 mm (MNHN-Pa 1287). — Stn DW 160, 19°46.0’S, 158°23.0’E, 35-41 m, 1.IX.1988, 1

9 mm (MNHN-Pa 1286).

New Caledonia. Surprise Atoll. LAGON, stn 455, 18°30’S, 163°08’E, 40 m, 28.II.1985, 1 juv. 5 mm (MNHN-Pa 1225).

Lagon Nord-Ouest. LAGON, Stn DW 1014, 20°8.7’S, 163°53.4’E, 22-23 m, 3.IV.1988, 1 10 mm ( RMNH D 48757). — Stn DW 1050, 20°9.9’S, 164°9.4’E, 11-12 m, 4.V.1988, 1 12 mm (MNHN-Pa 1319).

Lagon Est. LAGON, stn 836, 20°46.4’S, 165°15.75’E, 57 m, 11.I.1987, 1 8 mm (photographed; MNHN-Pa 1284). — Stn 710, 21°24.0’S, 166°02.5’ E, 30-31 m, 10.VIII.1986, 1 10 mm (photographed; MNHN-Pa 1265).

Lagon Sud-Ouest. LAGON, stn 13, 22°20’S, 166°29’E, 20 m, 22.V.1984, 1 10 mm (MNHN-Pa 1907). — Stn 62, 22°26’S, 166°26’E, 25 m, 20.VIII.1984, 1 9 mm (MNHN-Pa 1000). — Stn 79, 22°29’S, 166°29’E, 16 m, 21.VIII.1984, 1 14 mm (MNHN-Pa 1005). — Stn 155, 22°31’S, 166°38’E, 23 m, 24.VIII.1984, 1 11 mm ( RMNH D 48756). — Stn 233, 22°35’S, 166°46’E, 30 m, 22.X.1984, 1 ov. 13 mm (MNHN-Pa 1010). — Stn 279, 22°20’S, 166°27’E, 29 m, 9.XI.1984, 2

11 and 12 mm (MNHN-Pa 1905). — Stn 346, 22°45’S, 166°52’E, 40 m, 29.XI.1984, 1 9 mm,

1 10 mm (MNHN-Pa 1856). — Stn 553, 21°51’S, 166°55’E, 39 m, 16.VII.1985, 1 7 mm, 1 7 mm (MNHN-Pa 1247). — Stn 558, 22°46’S, 166°54’E,

43 m, 16.VII.1985, 1 8 mm (MNHN-Pa 1906).

DISTRIBUTION.— The species has a rather wide distribution in the Indo-West Pacific region: it is known from the Red Sea to Madagascar east to the Ryukyu Islands, the Philippines, Indonesia and New Caledonia. The species seems to be rather scarce (or

live in places that are not easily accessible) and so far

has been reported from Tor (= Et Tur) or Ras Mohammed, Sinai Peninsula, Egypt ( Paulson 1875, 1961), off Dubai, Persian Gulf, 25°10’N, 55°10’E and 24°55’N, 54°40’E ( Nobili 1905b, 1906a), environs of Port Louis, Mauritius ( Bouvier 1914, 1915), North Ubian Island, Sulu Archipelago, 6°7.5’N, 120°26’E

and between Salawati and Misool, Indonesia, 1°42.5’S, 130°47.5’E ( De Man 1905, 1916), Great Barrier Reef, Australia, about 0.25 mile N of N Direction Id, off Lookout Point near Cape Flattery, Queensland ( McNeill 1968). The present material greatly extends the known range of the species.

HABITAT.— The species has been found at depths between 12 and 57 m. The bottoms on which it occurred were described as sand (twice), coral, green mud, hard bottom with corals, hard rocks, soft bottom. It seems as if the species prefers a hard coralligenous substrate, but too few observations have been made to allow any positive statement.

DESCRIPTION

The rostrum is rather broad, the anterior margin is bilobed and behind the top it is slightly constricted. Dorsally it bears a distinct blunt rostral tooth.

Apart from the rostral tooth there are three more teeth in the midline of the carapace. The cardiac tooth is broad and two-topped; behind it is a double row of four or five flattened scale-like tubercles. The gastric tooth is single-topped and slightly stronger and higher than the cardiac. Behind and slightly lateral of the gastric tooth there are rather large squamiform tubercles, which are arranged in three or four longitudinal series of about three. The pregastric tooth is lower and smaller than either the gastric or rostral teeth, it is often broadly rounded, sometimes two- or three-topped. The branchial carina is rather widely interrupted by the cervical groove. No tubercle is placed in the gap, but a small one is present in the groove medially of the gap. Anteriorly the branchial carina ends in two about rectangular teeth of about equal size, which are placed one behind the other on the inner orbital margin. There is a row of three or four squamiform tubercles between the last of these orbital teeth and the cervical groove. The posterior branchial carina ends anteriorly in a blunt tooth, behind which there are several squamiform tubercles, often in three parallel rows of five to 10. At the place of the posterior submedian carina there is a group of squamiform tubercles. The intermediate row bears about three to five tubercles, some of which may be double; there are several other tubercles between the anterior branchial and the anterior postrostral carinae. The anterolateral angle of the carapace is rather blunt; behind it are two or three anterolateral tubercles. The lateral tooth behind the cervical groove is followed by one to three mediolateral tubercles. The tooth behind the postcervical incision is hardly larger than some of the six to eight posterolateral tubercles that follow it. Some tubercles may be seen between the posterior branchial and posterior lateral carinae. The intercervical carina is replaced by a group of squamiform tubercles which occupy the entire space between the cervical and postcervical grooves. There is a large, flattened often bilobed postorbital tubercle. The marginal groove at the end of the carapace is rather deep and narrow, before and behind it there are two transverse rows of tubercles. The posterior of these tubercles are often fused at their posterior end. The posterior margin of the carapace is shallowly incised in the middle.

The first abdominal somite has a complete transverse groove extending over its full breadth. Before this groove the surface of the somite is smooth, behind it there are about 20 longitudinal shallow grooves, which, however do not reach the posterior margin. The anterior half of the following somites also is smooth. The posterior half shows no median carina, but only the usual arborescent pattern of narrow, deep grooves. The median figure formed by the pattern is lobulated. The two halves of the dorsal surface of somites II to V meet each other in the median line under a very blunt angle, and seen in lateral view this median line is slightly arched; this curvature is most strongly pronounced in the fourth somite, where it is distinctly more convex than in either the third or fifth somites. The posterior margin of the first to fourth somites is deeply incised in the middle; this margin of the fifth and sixth somites ends in a blunt median point or is round- ed. The pleura of the first somite are short and bilobed, each lobe has its margin somewhat crenulated, this is more distinct in the anterior than in the posterior lobe. The other pleura end in a broad blunt, downward directed top. Apart from an indistinct lobe on the anterior margin of the second pleuron, the margins of the pleura II to V are entire. The arborescent pattern of the tergite extends on to the pleura. The sixth abdominal somite and the hard part of the telson bear several squamiform tubercles of various sizes. Of the two pairs of posterior teeth of the hard part of the telson the inner are slender and very distinct (sometimes their tip is rounded), they reach farther posteriorly than the outer teeth which usually are about rectangular and blunt.

Each half of the anterior margin of the antennular somite bears a blunt tooth in the middle; sometimes the margin shows one or two incisions at either side of this tooth.

The anterior margin of the last (sixth) segment of the antenna is only slightly convex; it bears five broad teeth, which have broad and blunt tops with little space in-between. The inner margin of the segment bears one or two blunt teeth. The antero-internal angle of the fifth antennal segment bears a blunt tooth which is carinate dorsally. The anterior margin of the fourth segment has five to seven teeth, the inner two of which are largest. The outer margin of this segment bears two or three blunt teeth (the apex of the segment not included), sometimes with an indication of a minute fourth tooth. This fourth segment has a strong oblique median carina running from the base of the segment to the apex; it shows tubercles over its full length. From its base a row of three or four tubercles extends outward and somewhat forward in the proximal half of the segment, a few tubercles are scattered over the distal part.

The anterior margin of the epistome shows a shallow incision in the middle, which sometimes makes the entire margin somewhat V-shaped.

P.1 is distinctly more robust than P.2. The dactylus of the second is very slender, being far longer than either that of the first or third, and more than twice as long as the one of the fourth leg. The dactylus of the fifth leg is shorter than that of the fourth. None of the dactyli bear any hairy fringe. The propodus of P.3 has a dorsal fringe of hairs; it is wider and more robust than the propodus of the other legs, which do not show the dorsal hairy fringe either. However, the propodus of P.3 is not broader than the merus. A fringe of dorsal hairs is furthermore present on the carpus of P.3 and P.4, and the merus of all legs. There are no ventral hair-fringes on any of the legs. The outer surface of the propodus and merus of P.3 shows two longitudinal hairy grooves; such grooves are present also on the merus of P.4. The outer surface of the merus of P.1, P.2 and P.5 shows only one such groove, which sometimes is rather indistinct.

The anterior margin of the thoracic sternum is V-shapedly emarginate, sometimes the emargination is more rounded with a narrow incision in the middle. No submedian tubercles are present in the incision, as found in Eduarctus n. gen. The anterior margin of the sternum is somewhat swollen and from either anterolateral tooth a carina extends posteriorly, the two carinae converging and forming an elongate V. The sternum is concave and shows no median tubercles. The posterior margin of the sternum is entire.

The first pleopods of the male (placed on abdominal somite II) are normal in shape; the endopods are rather large and elongate. The following pleopods have the endopods and exopods rudimentary, although in some specimens the endopods are longer than the exopods.

Size

In the examined material the cl. varied between 4 and 15 mm. Juveniles with cl. 4 and 5 mm were seen, males with cl. 6 to 12 mm (mostly between

8 and 11 mm), non-ovigerous females with cl. 7- 14 mm (mostly between 10 and 14 mm), and ovigerous females with cl. 11-15 mm. Paulson’s two males were said to be 19 mm long (probably total length). The material of Nobili (1905a, 1906a) and De Man’s (1905, 1916) specimens have been mentioned above. Bouvier (1915) gave the tl. of the adult female from Mauritius as 30mm. McNeill’s (1968) specimen has also been examined and is listed above.

Colour

De Man (1916: 92) described the colour as follows: “grayish coloured with a pale reddish tinge on the abdomen”. Paulson (1961: 103) gave as only colour description that “every joint of the five pairs of legs has a violet stripe”.

A colour photograph of the male specimen from Lagon Est, New Caledonia, stn 836, shows the carapace pale greyish brown with lighter and dark- er areas. Conspicuous are two rather small dark spots in the cervical groove one on either side of the cardiac tooth. Abdominal somites I to III also are pale brownish grey with a light area in the median part. Somites IV and V are reddish, somite IV with a whitish triangle (pointing back) in the middle, a similar but much smaller whitish triangle on somite V. Somite VI is rather evenly pale purplish grey, the tailfan is whitish. The dark band on the propodus of the visible walking legs is distinct.

An excellent coloured photograph was made of the male specimen from Lagon Nord-Ouest, New Caledonia (stn 1014). The ground colour of the body is a uniform grey olivaceous. Some very small white dots and many short whitish hairs show on the antennae. White dots are also scattered along the cervical groove and the posterior marginal groove. The abdomen shows a few very small white dots in the median line and near the base of the pleura. The two characteristic black dots mentioned in the previous description, are present here also, they show at either side of the cardiac tooth. On the pregastric tooth also a small dark dot can be seen. Furthermore there is a central small dark dot near the middle of the posterior marginal groove of the carapace. The first abdominal somite shows two distinct submedian dark brown spots, which are fused anteriorly. At either side of this median figure the first somite shows two thin, but distinct longitudinal dark lines; a rather distinct white spot is placed at the base of the pleura of the first somite. The sixth somite and the tailfan are grey, probably transparent.

A third coloured photograph was made of the male (cl. 10 mm) from Lagon Est, New Caledonia, stn 70. It is much less distinct than the previous photograph and shows a dark brown somewhat variegated animal with some small dark and very small white spots on the antennae. The dark dots on the pregastric tooth, those at either side of the cardiac tooth and the one just before the middle of the posterior margin of the carapace, are noticeable. The central figure on the first abdominal somite is quite distinct it consists of two dark spots joined anteriorly, while one can also just distinguish the two lines at either side of this central figure.

The specimens from Okinawa, after preservation in alcohol, were whitish with small black dots on the last two segments of the antennular peduncle. Small black dots are also found in the distal part of the teeth of the sixth antennal segment and near the top of the fourth segment. The dorsal surface of the carapace shows two rather large black spots, which cover the intercervical area. Two smaller dots are present, one on either side of the cardiac tooth. Most characteristic is the colour pattern of the posterior half of the first abdominal somite: in the centre it shows a dark horseshoe shaped spot with the closed end anteriorly; when the posterior part of the carapace covers the anterior part of the horseshoe, it looks as if there are two parallel black submedian lines. On either side of the median horseshoe-shaped spot the first segment shows two dark longitudinal somewhat curved lines; so that sometimes it looks as if there are six more or less parallel lines distributed equally over the segment. The anterior half of the first somite is darker than the posterior. There is a large dark spot on the fourth abdominal somite on either side of the hump.

In some Seychelles specimens the fourth and sixth antennal segments are dark with a pale rim. In the same specimens the carapace is quite dark with a white band along the anterior margin, and a light posterolateral area at each side; the tips of the larger teeth then often are also pale. The abdominal somites II to V are dark with a longitudinal whitish band in the median line; this band is widest on the second somite; here the tips of the pleura are whitish.

The legs have the usual dark band on ischium, merus, carpus and propodus, those of merus and propodus remain longest visible in preserved material, especially those of P.3 and P.4.

REMARKS

The nomenclature of the species is quite complicated. Paulson (1875), who was the first to report on the species, identified his Red Sea material as Scyllarus gundlachi von Martens, 1872 (= S. americanus S. I. Smith, 1869 ). Then, on 30 May 1905 Nobili, in a preliminary description of material from the Persian Gulf, published a description of the species, which he considered new, and used the name “ Scyllarus sordidus nov. spec. ” for it; he actually meant to name it S. nitidus but erroneously wrote sordidus . The name sordidus (in the combination Arctus sordidus ) had been used long before by Stimpson (1860) for a different species of Scyllarus . In August 1905 De Man described the species again as new (on material from Indonesia and the Philippines), using the name Arctus gibberosus . De Man realized that Nobili in May 1905 had made a mistake in naming his species S. sordidus , and he proposed Arctus nobilii as a new replacement name for S. sordidus Nobili, 1905 (non Stimpson, 1860). At the same time De Man noticed that A. nobilii was very close if not identical to his own A. gibberosus , and said that if the two should prove to be identical the name gibberosus should be used for the species in preference to nobilii . In his final paper on decapod and stomatopod Crustacea of the Persian Gulf, Nobili (30 April 1906 a: 59) explained his error in writing sordidus instead of nitidus , and on his pl. 6 fig. 31 the name nitidus is used, evidently by mistake, as in the rest of the paper (pp. 56-59, pl. 4 fig. 15) Nobili accepted De Man’s Scyllarus nobilii . He did not mention S. gibberosus . De Man (1916: 90, pl. 3 fig. 14) gave his definite description of Scyllarus gibberosus ; on p. 70 and 71 De Man discussed the possible synonymy of Arctus gibberosus De Man, 1905 and Arctus nobilii De Man, 1905 and concluded (p. 71): “When the two species afterwards once might prove to be identical, then the name of gibberosus has, of course, the priority”. The oldest available names given to the present species thus are Arctus gibberosus De Man, 1905 and Arctus nobilii De Man, 1905 . The relative precedence of these two names that were published simultaneously, is to be decided by the Principle of the First Reviser. The International Code of Zoological Nomenclature ( ICZN 1999) says on this account: “If two or more names […] are published on the same date […] the precedence […] is fixed by the First Reviser”. The definition of “First Reviser” is given in Art. 24.2.1. of the Code ( ICZN 1999) as follows “ the first author citing in a published work those names […] and selecting from them”. In the present case De Man (1905), who on p. 589 remarked that his Arctus gibberosus probably is identical with Nobili’s Scyllarus sordidus and in this case Nobili’s species may henceforth bear the name of gibberosus ; “when they are different, then I propose for the Persian species the name of Nobilii ”. Here De Man (1906) can be considered the first reviser himself as he gives precedence of gibberosus over Nobilii. There is a difficulty here as in the Glossary to the Code ( ICZN 1999: 115) the First Reviser is defined as “The first author to subsequently cite names [...] published on the same date and select one of them to have precedence over the other(s)”. The main difference with the definition given in Art. 24 of the Code ( ICZN 1999) itself is in the word “subsequent”, which figures in the Glossary but not in the Code. According to the Glossary De Man, 1906, cannot be the first reviser as his action of choice is simultaneously published with the two names, and not subsequently. Under the wording of the Glossary the First Reviser is De Man (1916: 71) who indeed is the first subsequent author who cites both the names gibberosus and Nobilii and gives precedence to the first. As the “first reviser action” by De Man (1906) is the same as that of De Man (1916), it is quite immaterial who actually is the first reviser, but for uniformity’s sake the Glossary should be adapted to the text of the Code. In the third edition ( ICZN 1985: 24) of the Code the word “subsequently” is in Art. 24 (b) but has evidently been removed by the editorial Committee of the fourth edition, while they forgot to do so in the Glossary. As the Glossary forms part of the new (4 th ed.) Code (see the Explanatory Note on p. xiii of the Code) there should be no differences in the definitions given in the two parts.

Anyhow, Scyllarus gibberosus is the valid name for the species; the names Scyllarus sordidus Nobili, 1905 , Arctus nobilii De Man, 1905 , Scyllarus paulsoni Nobili, 1906 and Scyllarus nitidus Nobili, 1906 all are invalid synonyms.

Figures

FIG. 69. — A, Eduarctus modestus (Holthuis, 1960) n. comb., Marquesas Islands, Nuka Hiva, MUSORSTOM 9, stn CP 1177, ovigerous carapace length 11 mm (MNHN-Pa 1826), photo P. Laboute; B, Eduarctus reticulatus n. gen., n. sp., New Caledonia, SMIB 8, stn 186, paratype, carapace length 12 mm (MNHN-Pa 1835), photo J.-L. Menou; C, D, Gibbularctus gibberosus (De Man, 1905) n. comb.; C, New Caledonia, LAGON, stn 1014, carapace length 10 mm (RMNH D 48757), photo P. Laboute; D, New Caledonia, Lagon Est, LAGON, stn 710, carapace length 10 mm (MNHN-Pa 1265), photo P. Laboute; E, Biarctus vitiensis (Dana, 1852) n. comb., New Caledonia, LAGON, stn 968, photo P. Laboute; F, Crenarctus bicuspidatus (De Man, 1905) n. comb., New Caledonia, Lagon Est, LAGON, stn 836,, photo J.-L. Menou.

FIG. 31. — Chelarctus crosnieri n. gen., n. sp., SW of Tongatapu, holotype (MNHN-Pa 1887); A-E, pereiopods 1 to 5. Scale bar: 2 mm.