Pseudanthessius anormalus   Ummerkutty,  1967 (Copepod)
Organism information awaits expert curation
Class: Maxillopoda

Size: 0.75 mm (female).

Genital segment is slightly broader than long, the narrow posterior division being short compared to the anterior broad division. Caudal ramus is slightly broader than long and is distinctly shorter than te last urosomal segment. Endopod of the fourth leg is slightly swollen in the proximal half but has no notch or knob. Fifth leg consists of a highly reduced spine seen only from the ventral side and 2 unequal setae, one which is jointed at base.

Female: Prosome is broadly oval, cephalosome contributing more than half the total. Posterior margin of cephalosome is the widest part of body, next three free metasomal segments diminishing in length and width successively backwards. Urosome is 5-segmented, first segment bearing the fifth pair of legs. Genital segment is very broad and its length exceeds that of the abdominal segments combined. The narrower posterior division of the genital segment is very short compared to the broad anterior part. Caudal rami are peculiar. They are hardly as long as broad and are distinctly shorter than the last abdominal segment. Caudal setae are fairly long, the middle two setae being jointed near their base. Antennule is 7-segmented. Antenna is 4-segmented, terminal segment bearing two spines and a few setae. First and second segments are each with a single small seta and the third with two setae and several hairs. Mandible and maxillule show little peculiarities. In the maxilla both the terminal lappet and the process just behind it carry spinules on their anterior margin. Maxilliped apparently 2-segmented, the first segment is naked, the second segment carries on seta in the middle of the posterior margin and two stout spines on the innermost part.
Swimming legs are present. The 1-segmented endopod of the fourth leg is slightly swollen in the proximal region, but no-knob or notch is present. The second endopod segment of first, second and third leg is produced at its outer distal angle into a beak-like structure. Fifth legs are rather modified; the spine is very much reduced and is seen only if observed ventrally; on the upper and lower sides of this reduced spine are borne two setae, the much longer one being jointed at base.

Synonym (s)

Common Name (s)
Economic Importance and Threats



• Tamil Nadu, Gulf of Mannar INDIA (Record: 19/10/1960)
• Tamil Nadu, Vedalai INDIA (Record: 19/10/1960) (Depth: 2 mts)

Literature Source(s)
  • Ummerkutty, ANP (1966) Description of two species of cyclopoid copepods, Pseudanthessius anormalus n. sp. and P. brevicauda n. sp. Proceedings of Symposium on Crustacea Marine Biological Association of India, Mandapam Camp Part I 107-113 Available at - NIO, Goa
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • James, PSBR ; Thomas, PA ; Pillai, CSG and Achari Kumaraswamy, GP (1969) ´╗┐Catalogue of types and of sponges, corals, polychaetes, crabs and echinoderms in the reference collections of the Central Marine Fisheries Research Institute Bulletin of Central Marine Research Institute CMFRI, Cochin 7 1-66 Available at -

Page last updated on:2011-03-11

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