Tetraloides nigrifrons   (Dana,  1852) (Crab)
Organism information awaits expert curation
Class: Malacostraca

External maxillipeds with ischium of endognath nearly a parallelogram, proximal margin obliquely truncate, inner distal angle strongly produced,rounded; lateral margins subparallel, distal margin slightly excavate. Inner distal angle of merus markedly truncate,outer distal angle strongly produced and rounded.

Carapace immediately behind front feebly granular. Anterolateral margins almost parallel in males, slightly constricted in front in adult females, divergent in juvenile specimens, adults lack lateral spines. Interorbital submedian lobes triangular, outer lobes very shallow. No hiatus between outer lobes and superior orbital angle. Evenly spaced minute denticles, successively larger laterally, edge front. Orbits large, oblique. Postorbital angle acute, projecting outward. Inferior orbital angle developed into triangular tooth, its apex strongly deflected outward, in juveniles acute tip projects beyond frontal margin. Lower lip of antennular fossets minutely gradulate. Basal article of antennae granular, extending as far as middle of interior orbital tooth. Inner distal angle of basal article obliquely truncate, excavate.

External maxillipeds with exognath slender, tapered distally with a broad blunt triangular tooth at internal distal margin. Chelipeds markedly unequal. Merus rounded, anterior margin granulate, crested. Anterior internal border of carpus granulate; few larger granules, nearly blunt spines, commonly on carpus of smaller chela. Manus of large chela massive, rounded, finely granulate. Upper margin of manus rounded, lower margin carinate. Rows of larger granules causing a serrulate lower margin. Dactyl and immovable finger bearing rudimentary teeth on proximal portion of cutting edge. Sometime males having fingers with an elongate oval gape, meeting only at tips. Manus of smaller chela narrow, laterally compressed; cutting edges, furnished with few shallow teeth, meet throughout their length. Ambulatory meri laterally flattened, almost foliaceous, their upper margins cristate. Carpal and propodal articles wide. Lateral distal end of propodus near dactylar articulation armed with strong stout spines. Dactyls stocky, tapered. Blunt, horny, hoof-like tip, flattened, medially grooved. Inferior distal surface of dactyl decorated with chitinous setae arranged in three discontinuous transverse bands. Superior distal surface just behind tip with several curved spinules. First male pleopod with anteriorly pointing setae on external distal margin longer than on internal margin.

Obligate symbionts of Acropora Corals.

Synonym (s)
Tetralia nigrifrons Dana, 1852a

Common Name (s)
Economic Importance and Threats

Habitat:  Reef Associated


• Lakshadweep INDIA
• Andaman and Nicobar Islands INDIA

Literature Source(s)
  • Jeyabaskaran, R; Wafar, S and Wafar, M (2002) CD on Brachyuran Crabs of West Coast, India Available at - http://www.nio.org/Biology/brachyuran/index.html
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at - http://www.marinespecies.org

Page last updated on:2010-11-22

Back to Search