Cryptodromia trituberculata Buitendijk, 1939

Mclay, Colin L., 2001, Dynomenidae and Dromiidae (Decapoda, Brachyura) from Guam, Philippine Islands, Tonga and Samoa, Zoosystema 23 (4), pp. 807-856 : 836-838

Cryptodromia trituberculata Buitendijk, 1939

( Fig. 7 )

Cryptodromia trituberculata Buitendijk, 1939: 226 , pl. 7, figs 2, 3. — McLay 1993: 199 (key).

A B

A, B, E

F

D, F

D E

MATERIAL EXAMINED. — Indonesia. Obi Latoe, shore or reef, 23-27.IV.1930, 1 4.5 × 4.0 mm (holotype, RMNH, Crust. 4198).

Philippine Islands. Albatross, stn D 5145, no depth, 1908, 1 4.3 × 4.3 mm (sponge cap) ( USNM).

SIZE. — The male holotype, 6.8 × 6.4 mm, is the largest known specimen. The Albatross male is small-

er than the type. No C. trituberculata females are known.

DEPTH AND HABITAT. — Shallow water. Carries pieces of sponge as camouflage.

DISTRIBUTION. — Previously known from Indonesia. Now known from the Philippine Islands.

DESCRIPTION

Carapace about as wide as long or slightly wider than long, convex and covered with short tomentum, branchial groove distinct. Rostrum tridentate, median tooth strongly deflexed, hardly visible dorsally. Lateral rostral teeth blunt, separated by broad sinus, almost continuous with supraorbital margin which is interrupted by a small supraorbital tooth. Margin concave to small, blunt postorbital tooth. Supraorbital margin fringed with long setae. Fissure separates infraorbital margin, armed with well-developed tooth, not visible dorsally. Sub-hepatic area minutely granulated, with a small tubercle beneath postorbital corner and another suprasutural tubercle lower down. Anterolateral margin begins below level of postorbital corner, convex, armed with three broad, blunt teeth. Carapace widest across third teeth. No posterolateral tooth, posterior carapace margin straight.

First article of antenna wider than long, beaked medially, not gaping. Second article longer than wide, disto-medial corner produced on which third article is inserted, diagonal ridge from lateral proximal margin towards base of third article. Exopod deeply bilobed to accommodate rest of antenna, curving over base of eyestalk.

Chelipeds small, outer face of carpus with two blunt proximal tubercles, and two larger, sharp distal tubercles. Outer face of propodus minutely granular with large proximal tubercle and anoth- er at base of dactyl. Fingers long, pearly-white, not gaping widely, fixed finger armed with seven or eight small teeth, margin of moveable finger largely edentate. Legs minutely granulated not verrucose. P2 and p3 similar in size to chelipeds, propodi short, broad, inner margins of dactyli armed with three short spines. Dactyli strongly curved at tips. P4 and p5 shorter, p5 much longer than p4. Dactyli opposed by single propodal spines, with another short spine on outer propodal margin at base of dactyl.

Outer surface of abdomen minutely granular. Posterior telson margin of male truncate. Posterior corners of fifth abdominal segment with strongly produced tubercles. Uropods welldeveloped, visible externally, utilized in abdomi- nal locking mechanism by fitting in front of coxal ridges on coxae of p2. Female of this species is unknown.

DISCUSSION

Buitendijk (1939) pointed out that anterolateral teeth in Cryptodromia trituberculata may be different on each side of the carapace. On the right side of the type specimen the three broad teeth are of equal size, but on the left the first tooth is smaller than the corresponding one on the other side. This species resembles C. mariae in the shortness of the median rostral tooth, but C. trituberculata lacks the subhepatic and suprasutural tubercles. Also the second anterolateral tooth in C. mariae is very small.

Figures

FIG. 7. — Cryptodromia trituberculata Buitendijk, 1939, Indonesia, Obi latoe, shore or reef, 4.4 × 4.1 mm; A, dorsal view of carapace; B, ventral view right orbital and sub-hepatic area (antenna only shown diagrammatically); C, outer face of left cheliped; D, posterior view of distal articles of left second pereopod; E, posterior view of distal articles of right third pereopod; F, dorsal view of posterior abdominal segments and telson (posterior margin damaged and therefore indicated by dashed lines) (holotype, RMNH, Crust. 4198). Scale bars: A, C, 1.0 mm; B, D-F, 0.5 mm.