Lauridromia indica ( Gray, 1831 )

Mclay, Colin L., 2001, Dynomenidae and Dromiidae (Decapoda, Brachyura) from Guam, Philippine Islands, Tonga and Samoa, Zoosystema 23 (4), pp. 807-856 : 823-826

Lauridromia indica ( Gray, 1831) ( Fig. 4 A-F)

Dromia indica Gray, 1831: 40 . — Griffith & Pidgeon 1833: 296, crust. pl. 24, fig. 2.

Dromia sp. – White 1847: 55.

Dromia gibbosa H. Milne Edwards, 1837: 175 . — Alcock 1901: 75 (list). — Ihle 1913: 89 (list).

Dromia (Dromidia) orientalis Miers, 1880: 370 , l. 15, figs 1, 2.

Dromidia cranioides De Man, 1888b: 208 , pl. 14, figs 6-8. — Nobili 1903: 22. — Rathbun 1910: 366; 1911: 194.

Dromia cranioides – Alcock 1900: 138; 1901: 46, pl. 2, fig 5.

Dromidia indica – Alcock 1901: 76 (list). — Ihle 1913: 90 (list).

Dromidiopsis cranioides – Borradaile 1903: 299 (list). — Ihle 1913: 26, pl. 1, fig. 4, text figs 8a, 9, 18. — Sakai 1936: 12; 1976: 10, text fig. 1. — Buitendijk 1950: 59. — Serène & Lohavanijaya 1973: 19, figs 8-16, pl. 2, B-D. — Dai et al. 1981: 131, text figs 3-4, pl. 1, fig 2. — Dai & Yang 1991: 18, pl. 1 (3), fig. 4 (4-5).

Dromidia orientalis – Ihle 1913: 90 (list).

MATERIAL EXAMINED. — Indian Ocean. No exact locality, no depth, no date, 1 38.1 × 40.2 mm (holotype of Dromia indica Gray, 1831 , BM 304a, dried collection, presented by General Thomas Hardwicke.). — Western Indian Ocean, HMS Sealark, 7 m, 1905, coll. J. Stanley Gardiner, 1 6.7 × 7.2 mm ( USNM 41044).

Indo-Malayan Seas. No exact locality, no depth, no date, 1 63.6 × 59.4 mm ( BM 1880: 6) (holotype of Dromia (Dromidia) orientalis Miers, 1880 ).

Singapore. Johore Strait , off Seletan , 16.IV.1933, coll. M. Tweedie, 2 13.0 × 14.0, 17.0 × 17.2 mm, 2 13.0 × 14.3, 17.1 × 17.7 mm ( ZRC 196461115-6 ). — Siglap, VI.1933, coll. M. Tweedie, 5 14.7 × 15.1-25.8 × 26.4 mm, 5 16.8 × 16.0-40.2 × 40.0 mm ( ZRC 19646115-14 ). — Tuas, 18. VI.1982, coll. W. Lee, 2 38.5 × 38.8, 81.0 × 76.0 mm, 8 52.5 × 53.0 to 63.8 × 63.8 mm, 1 (ovig.) 63.0 × 62.5 mm ( ZRC 1984.5700 - 5709 ) ; 14.VII.1982, coll. W. Lee, 1 80.0 × 72.5 mm ( ZRC 1984.5643 ) ; 8.IX.1982, coll. W. Lee, 1 82.5 × 76.5 mm, 1 (ovig.) 67.0 × 66.4 mm ( ZRC 1984.57 - 11-5717 ) ; 1.X.1982, coll. W. Lee, 1 79.7 × 72.5 mm ( ZRC 1984.5830 ) ; 13.X.1982, coll. W. Lee, 3 67.0 × 63.0-78.0 × 69.8 mm, 2

64.5 × 65.0, 69.0 × 69.8 mm ( ZRC 1984.6843 - 6848 ) ; 15.II.1984, coll. W. Lee, 7 34.0 × 34.3- 80.0 × 72.3 mm, 1 35.0 × 35.2 mm ( ZRC 1984.5874 - 5884 ) ; 20.III.1984, coll. W. Lee, 1 27.0 × 27.8 mm, 1 39.4 × 40.5 mm ( ZRC unregistered) ; 5.VIII.1984, coll. W. Lee, 1 59.0 × 56.5 mm, 3 52.8 × 51.5-58.0 × 58.2 mm ( ZRC 1984.35 - 38 ) ; 16.II.1984, coll. W. Lee, 1 55.0 × 52.3 mm ( ZRC 1984.5894 ). — Southern Islands , 1985, coll. P. Ng, 1 17.0 × 18.0 mm ( ZRC 1985.1726 ). — Off Singapore, 30. V.1991, coll. P. Ng, 1 53.5 × 51.5 mm, 1 61.5 × 60.5 mm, 2 (ovig.) 54.5 × 54.2, 63.7 × 63.1 mm. — South West Johore, 1992, coll. T. Tan & D. Spiegel, 1 45.5 × 44.4 mm, 1 44.5 × 45.3 mm ; 28.I.1994, coll. R. Teo & M. Sin, 1 18.9 × 19.4 mm (sponge cap). — Sultan Shoal, 26.II.1994, coll. R. Teo & M. Sin, 1 32.5 × 33.1 mm (sponge cap). — Between P. Tekong & Changi, 26.I.1994, coll. D. Lane, 1 30.3 × 30.4 mm (compound ascidian cap). — P. Ubin, east Singapore, 26.XII.1995, coll. A. Wong, 1 12.5 × 13.7 mm (compound ascidian cap) ( ZRC unregistered) .

Thailand. Off Pattaya, 25.XII.1991, coll. P. Ng & L. B. Holthuis, 1 32.0 × 33.0 mm (ZRC unregistered).

Philippine Islands. 1 30.8 × 31.8 mm (BM 43.6, dry collection, purchased from Mr Cuming). — Sulu Archipelago, Tawi Tawi Group, Albatross Expedition, stn D 5163, 4°59.10’N, 119°51.00’E, 51 m, 24.II.1908, 1 7.2 × 8.0 mm (USNM 296458).

SIZE. — Maximum size for females is 67.0 × 66.4 mm, and for males 82.5 × 76.5 mm. Females and small males (less than cw of 50 mm) tend to have cw about the same as cl, but larger males have cw> cl. Females carry a large clutch of eggs: the largest ovigerous female, 67.0 × 66.4 mm, had approximately 13,000 eggs. Egg diameter is 0.75 mm. Near Singapore, ovigerous females have been collected from May to July. The first zoeal stage of Lauridromia indica has been described by McLay et al. (2001).

DEPTH AND HABITAT. — Depth range is from 7 m to around 90 m. Ihle (1913) provides the deepest record of 61-91 m, but most specimens are found at shallower depths. Habitat is among coral reefs where sponges are found. L. indica carries pieces of sponge, usually much larger than itself.

DISTRIBUTION. — Amirante, India, Andaman Sea and Mergui Archipelago (type locality of De Man’s species), Singapore, Gulf of Thailand, New Guinea, Java Sea, South China Sea, and China. Now known from the Philippine Islands. Balss (1922: 106) refers to a specimen supposedly from Sagami Bay, Japan, but Sakai (1936, 1976) remarked that he has never found any specimens, even amongst the vast collection of the Emperor of Japan. Thus the occurrence of L. indica in Japanese waters remains doubtful.

DESCRIPTION

Carapace as wide as long (wider than long in large males), globose, strongly convex, rising steeply behind rostrum and beside anterolateral margins. Surface smooth, branchial groove shallow, lateral cardiac borders faintly marked, and distinct pit in inner branchial area. Posterior cardiac area with three small protuberances arranged in a triangle. Whole body covered with short velvety tomentum which may be eroded in some places and with tufts elsewhere. Rostrum tridentate, median rostral tooth short, deflexed but visible dorsally, lateral teeth short, blunt and longer than median tooth. Shallow frontal groove runs back between two rounded swellings. Sub-hepatic area smooth, swollen above pleural suture. Anterolateral margin begins at level of infraorbital margin, evenly convex, with four or five acute teeth. Position and size of anterolateral teeth variable (see below). Posterolateral tooth acute, anterolaterally directed, preceded by pronounced sinus leading to branchial notch. Posterolateral margins slightly convergent.

Supraorbital margin slightly concave, interrupted by small, blunt tooth, no postorbital tooth. Deep fissure at postorbital corner, infraorbital margin with blunt tooth near inner edge, and slightly visible dorsally. Basal article of antenna wider than long, beaked medially; second article much longer than wide, convex, curving over base of eyestalk, distomedial corner produced, acute; third article inserted at an angle, ratio of length of antenna to cw= 0.35-0.45. Epistome triangular, concave, as long as wide, lateral margin grooved mid-way. Crista dentata with 12 large teeth.

Chelipeds well-developed, massive in male, merus triangular in cross-section, borders tuberculate; outer face of carpus with two large distal tubercles on outer face, upper border with three or four tubercles and inner distal margins with three small tubercles; propodus smooth except for three to five prominent tubercles on inner margin of superior border. Fingers down-curved, maybe pink, outer surface longitudinally grooved, margins bearing six to eight inter-locking teeth with a proximal gape.

P2-p3 shorter than chelipeds, smooth, dactyli as long as propodi, inner margins of dactyli with seven or eight small spines increasing in size distally, outer margins with two divergent rows of stiff setae. P4-p5 shorter than p2-p3, p4 shortest.Dactyl of p4 opposed by large propodal spine with two smaller spines on outer propodal margin. Dactyl of p5 opposed by two unequal propodal spines, with small- er spine on outer propodal margin and a large accessory spine on outer margin of dactyl itself.

Male telson longer than wide, truncate; uropods large, visible externally. Abdominal locking mechanism consist of serrated ridges on coxae of p2-p3, grasping distal telson border and distal notch in penultimate abdominal segment, uropods not involved. Female telson much wider than long, posterior margin rounded, uropods visible externally. Strong abdominal ridge, joint between fifth and sixth segments almost totally fused, suture only evident at margins.

Female sternal sutures 7/8 convergent, parallel anteriorly, diverging slightly before ending on prominent tubercles joined by connecting ridge just behind bases of chelipeds.

DISCUSSION

Serène & Lohavanijaya (1973) referred their material from the South China Sea and Gulf of

Thailand to Dromidiopsis cranioides (De Man, 1888) . They listed Dromia (Dromidia) orientalis Miers, 1880 as an uncertain synonym of Dromidiopsis cranioides . However, McLay (1993: 145) showed that both of these species are in fact synonyms of Dromia indica Gray, 1831 . Gray (1831) did not give the sex of the type, but in fact, it is a male. Griffith & Pidgeon (1833: 296) say that their figure of Dromia indica is based on “a specimen in the possession of General Hardwick”. This may well be the type specimen, although the figure has no scale bar and they do not give any dimensions.

Dromia gibbosa H. Milne Edwards, 1837 was originally described as follows: “Carapace très fortement bombée et sans bosselures notables en dessus; dents frontales saillantes et pointues; la dent orbitaire supérieure et celle formée par l’angle supérieur de la fissure orbitaire externe pointues et saillantes; la dent orbitaire inférieure petite et obtuse. Bords latéro-antérieurs armés de cinq ou six petites dents coniques; l’espace entre les deux dernières occupant plus du tiers de la longueur totale de ce bord. Bords latéro-postérieurs beaucoup plus courts que les bords latéro-antérieurs. Pattes antérieures médiocres et à peine bosselées; bord supérieur de la main armé de cinq ou six pointes; pattes suivantes médiocres. Abdomen du mâle sans gouttières latérales, bien marquées; le dernier article triangulaire et presque équilatéral; pièces latérales rudimentaires”. There are enough details in the above description to confidently say that D. gibbosa is almost certainly the same as D. indica Gray, 1831 . The type specimen of D. gibbosa , without locality, has recently been re-discovered in the dry collection of the MNHN (D. Guinot pers. comm.). As a footnote to his description of D. gibbosa, Milne Edwards (1837) suggested that his species may be the same as Dromia aegagrophila [sic] Fabricius, 1798. However, this is very unlikely and D. aegagropila (correct spelling) probably belongs to Austrodromidia McLay, 1993 .

In Lauridromia indica , there is wide variability in the number, shape and arrangement of teeth on the anterolateral margin. Sometimes the teeth on the two sides of the carapace are different. Serène & Lohavanijaya (1973) state that in their two specimens there were four anterolateral teeth, although on a lower level, there were two accessory teeth on the right, or one on the left, between the first and second anterolateral teeth. The same accessory teeth were noted by Alcock (1900, 1901) and Buitendijk (1950) also found variation in two large males from Singapore, which had up to six teeth. The same variation was noted in the material examined herein (see Fig. 4 ). In males, the shape of the carapace also changes as they grow larger. Small males and all females have a cw approximately equal to cl, but in large males the cw is significantly larger than cl. This difference is clearly illustrated in the figures of Alcock (1901: pl. 2, fig. 5) and Ihle (1913: pl. 1, fig. 4) which appear to be quite different. Both specimens are males but Ihle’s specimen is much larger. This lead Sakai (1976: 10) to say that Ihle’s material belonged to a species of Cryptodromia . But this cannot be true because all species of Cryptodromia are quite small whereas the species of Lauridromia grow to a much larger size. The variability and growth changes in relative dimensions of the carapace have contributed to the problems of clearly defining the species and to determining the correct name for L. indica .

Serène & Lohavanijaya (1973: figs 14, 15) figured the first and second gonopods of L. indica . The first gonopod is stout and setose, especially around the tip, forming a partially developed tube. There are no unique features of this appendage which is very similar to that found in most other dromiids except the species of Sphaerodromia . The styliform second gonopod is longer than the first and, when inserted, it emerges from the tip of the first. The shaft of the second gonopod is unarmed.

Figures

FIG. 4. — Lauridromia indica (Gray, 1831), Indo-Malayan Seas, no definite locality, 63.6 × 59.4 mm; A, dorsal view of carapace; B, outer face of right cheliped; C, dorsal view of right cheliped; D, posterior view of right second pereopod, dactyl; E, posterior view of left fourth pereopod, propodus and dactyl (the two spines on the outer propodal margin have broken off so they are indicated by dashed lines); F, posterior view of left fifth pereopod, propodus and dactyl (holotype of Dromia (Dromidia) orientalis Miers, 1880, BM 1880: 6); G, Johore Strait, off Seletan, 13.0 × 14.0, 17.0 × 17.2 mm (left to right) dorsal view of right side of carapace (ZRC 196461115); H, Tuas, Singapore, 27.0 × 27.8 mm, 39.4 × 40.5 mm (left to right) dorsal view of right side of carapace (ZRC unregistered). Scale bars: A-C, 10 mm; D-F, 5 mm; G, 2 mm; H, 4 mm (left) & 7 mm (right).