Arenosetella tricornis   Wells & Rao,  1987 (Copepod)
Organism information awaits expert curation
Class: Maxillopoda

Size: length (female): 525 ┬Ám

Body linear and elongate. Cephalothorax rectangular, not attenuated anteriorly. Except for the pseudoperculum and a single circum-segmental row of minute setules on the third abdominal segment the body is unornamented. Abdominal segments with a digitate hyaline frill. Pseudoperculum parabolic and minutely pubescent. Last segment with a dorsal armature of three pairs of more or less straight spines which all appear to form one entire apparatus. Rostrum acute.

Antennule: Six-segmented. First segment short and broad with a long plumose seta, which is broad proximally and attenuated distally, at the inner distal corner.

Antenna: Coxa, basis and first endopod segment bare. Second endopod segment with two pectinate spines on the inner side and with three geniculate and three straight pectinate setae terminally. Exopod three-segmented, the first without a seta. Second segment short and with a pectinate seta at the inner distal corner. Third segment elongate with one pectinate and one plain terminal setae.

Mandible: Palp well developed. Basis with three long setae and with long setules along the inner edge. Endopod with three setae set close together on the inner edge, one plumose seta on the outer edge and four setae terminally and subterminally. Exopod small; outer edge with long fine setules. Exopod with three setae, two of which are plumose and with the middle seta fused to the ramus.

Maxillule: Precoxal arthrite with four stout spines, one of which is pectinate. Basis with five setae. Exopod with two and endopod with five setae.
Maxilla: syncoxa with three endites, the middle one represented by a single seta. Basis very long, with two plumose setae and a spine near the base of the inner edge. Endopod with two strong curved setae and two finer setae.

Maxilliped: Basis short and broad with a long slender seta at the inner distal corner. First endopod segment slender and elongate; inner edge with fine setules. Second segment about half as long as the first, with two terminal setae and one outer seta.0

P.1-P.4: Coxa with strong spinules at the outer distal corner. Basis with a weak outer seta and, in P.1 only, a weak inner seta. Both rami three-segmented, exopods reaching to the end of the second endopod segment. Endopod segments, particularly the first, stouter than the exopod segments, but all are elongate and relatively slender. Outer edge of all segments spinulose, those of the exopod being elongate. P.5 small with the rami fused together. Inner expansion of the basendopod with two setae. Exopod with three terminal setae and an accessory seta on the anterior surface. All setae elongate.

Male: Slightly smaller than female.

Abdomen: First two segments distinct, the first segment with a difitate hyaline frill as on the other segments.
Antennule chirocerate.

P.5 smaller than that of the female and with different setal proportions. Inner exopod seta plumose. P.6: The pair of P.6 are confluent, with two setae and two teeth on each side.

Synonym (s)

Common Name (s)
Economic Importance and Threats



• Andaman and Nicobar Islands INDIA

Literature Source(s)
  • Wells, JBJ and Rao, GC (1987) Littoral Harpacticoida (Crustacea: Copepoda) from Andaman and Nicobar Islands Memoirs of the Zoological Survey of India ZSI 16(4) 1-385; figs 1-1 Available at - NCL, Pune
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -

Page last updated on:2010-06-30

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