Nannocalanus minor f. minor   Sewell  (Copepod)
Organism information awaits expert curation
Taxonomy
Kingdom:Animalia
Phylum:Arthropoda
Class: Maxillopoda
Order:Calanoida
Family:Calanidae

Image copyrights: Biotech Books

a. The whole animal from the right side

Description
Size(female): length 1.32 to 1.49 mm

The proportional lengths of the cephalothorax and abdomen are as 24 to 17, the abdomen being contained 3.2 times in the length of the anterior region of the body, as in the larger form. The general conformation of the body agreed with that of the larger form with this very slight difference that the posterior margin of the last thoracic segment does not form a uniform curve, but exhibits a faint tendency to be produced at the apex of the curve.
The genital aperture is guarded by a valve flap that is very distinctly narrower than in forma major and only reaches across a little more than one-half of the ventral surface, while the transverse diameter of the valve is only one and a quarter times that of the antero-posterior diameter, instead of one and a half-times as in the larger form.
The 1st antenna reaches back to the hinder margin of the genital segment and, as in forma major, segments 1 and 2 are separate and 8 and 9 are fused. The 2nd antenna, mouth-parts and the 1st swimming leg appear to be identical with those of forma major.
The 2nd swimming leg in this form exhibits a considerable difference from that of forma major in the degree of development of the marginal spines on exopod 1 and 2; these are considerably smaller than in the larger form and the marginal spine on exopod 1 reaches to a level of the junction of the middle and distal thirds of the outer margin of exopod 2, while that on exopod 2 reaches only a little more than half the distance to the point of origin of the proximal spine on exopod 3.
The 5th swimming leg closely resembles that of the larger form; the serration of the inner margin of the 1st basal segment is identical and the degree of development of the marginal spines is also similar, but the end-spine is distinctly shorter; its length being contained 1.41 times in that of the 3rd segment of the exopod.



Synonym (s)

Common Name (s)
Economic Importance and Threats

Ecology

Biogeography


• INDIA (Record: 1910-1925)

Literature Source(s)
  • Sewell, RBS (1999) The copepoda of Indian seas Biotech Books, Delhi, India 407 pp Available at - NIO, Goa
  • 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:2009-07-24

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