Uca acuta   (Stimpson,  1858) (Crab)
Organism information awaits expert curation
Class: Malacostraca

Image copyrights: Crane, J

A single, long groove running laterally almost entire length of major dactyl, the subdorsal groove being short; chela tip forceps-like, because of an opposable series of enlarged tubercles, but not strikingly so Gonopod with anterior flange large, posterior rudimentary; inner process minute, scarcely reaching base of flange. Floor of orbit without tubercles, although occasionally with a few, minute, irregular granules and always with a prominent blunt ridge or mound on inner third. Carapace with fronto-orbital margin only slightly oblique, almost straight in comparison with that of rosea; antero-lateral margins well developed.

Male: Carapace. Frontal groove wide or narrow, its sides parallel or slightly convergent. Fronto-orbital margins slightly oblique; antero-lateral angles acute to varying degrees, moderately produced; antero-lateral margins short but definite, finely or not at all serrate, moderately converging, then turning sharply to form strongly converging dorso-lateral margins which are beaded or smooth. Vertical lateral margin extending almost to dorsal surface, beaded throughout except, in some individuals, in upper portion. Eyebrow traceable through more than half of orbit; upper margin strong, and either finely beaded or smooth; lower margin indistinct, granulate. Suborbital margin less sinuous than usual in Deltuca; crenellations present on outer half of orbit only, separate, broad and spatulate, not continuing externally beyond angle. Tubercles on floor of orbit absent or, rarely, barely traceable as irregular fine granules; a blunt ridge or mound running up to one-third width of orbit on its floor, at inner side behind margin. Major cheliped: Merus with a row of tubercles, slightly enlarged distally on antero-dorsal margin; distally with one or two short, irregular rows of tubercles on anterior surface; latter surface with other small tubercles, especially near ventral margin, variable in distibution and size; ventral row of tubercles single or compound. Tubercles of outer palm relatively small compared with other Deltuca, notably large only near pollex base; smaller tubercles extending proximally onto pollex and dactyl. Inner surface of palm between ridges covered with small, low tubercles. Depression at pollex base a longitudinal trench rather than clearly trifid. Outer side of dactyl with subdorsal groove short, lined with tubercles. In gape, a median pollex tooth and several proximal teeth on dactyl usually enlarged in branchychelous individuals; subdistally the edges of dactyl and pollex become suddenly closely apposed, the margins being straight, not concave; they are furnished with corresponding series of slightly enlarged teeth, the most proximal pair in the group largest, giving a distal forceps-like formation which is distinct but not extreme. Outer distal pollex without submarginal carina. Minor Cheliped: Merus with serrations of dorsal margin well separated, those of postero-ventral less so. Carpal and dactyl ridges present or absent. Ambulatory legs: Merus. Antero-ventral ridge on 1st leg absent proximally, represented distally by separated fine serrations; corresponding serrations on 2nd, 3rd, and 4th legs weak or moderate. Carpus. Dorsal ridges weak or moderate; posterior ridges present or absent. Gonopod: Inner process small, scarcely projecting onto horny surface of flange base; anterior flange large, curving moderately forward, its breadth greater than diametre of pore; posterior flange very small; thumb short, subdistal, barely reaching base of flange.

Female: Gonopore externally with a raised rim.

Synonym (s)
Gelasimus acutus Stimpson, 1858b
Uca demani (not Ortmann, 1897)
Uca arcuata (not de Haan, 1833)
Uca (Deltuca) acuta acuta Crane, 1975

Common Name (s)
Economic Importance and Threats

Habitat:  Estuarine


• Gujarat, Medi-Sinthodi Creek (Lat: 23.45) (Long: 68.48) INDIA (Record: 1999-2000)

Literature Source(s)
  • Saravanakumar, A; Serebiah, JS; Thivakaran, GA and Rajkumar, M (2007) Benthic macrofaunal assemblage in the arid zone mangroves of Gulf of Kachchh – Gujarat Journal of Ocean University of China Ocean University of China 6(3) 303 -309 Available at - http://dx.doi.org/10.1007/s11802-007-0303-3
  • Marine Species Identification Portal Available at - http://species-identification.org/
  • 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:2011-03-03

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