Scolecithricella ctenopus   (Giesbrecht)  1888 (Copepod)
Organism information awaits expert curation
Class: Maxillopoda

Size (female): length 1.26 mm

The proportional lengths of the cephalothorax and abdomen are as 110 to 23, the abdomen being thus containded 4.8 times in the length of the anterior region of the body.
The body is moderately robust and when viewed from above is oval in shape, tapering towards both ends. The head and 1st thoracic segment are fused, but a slight trace of the line of fusion can be detected in the mid-dorsal region. Thoracic segments 4 and 5 are also fused, but a well-marked notch in the ventro-lateral margin indicates the limit of each segment. The posterior thoracic margin is produced backwards and terminates on each side in a small curved spine.
The abdomen is very short in the present specimen owing to the various segments being considerably telescoped into each other.
The rostral filament are delicate and are difficult to see, owing to their being in close approximation to the swollen basal segments of the 1st antennae.
The 1st antennae reach back to the tip of the furcal rami. They consist of 23 segments.
In the 2nd antenna the endopod is only 3/4th the length of the exopod.
In the 2nd maxilla the terminal segment bears a number of sausage shaped filaments.
The maxilliped is comparatively small; the 1st basal segment bears a row of setae along its anterior margin near the proximal end. From the middle lobe spring two setae, of which the proximal is dilated about half-way along its length and then appears to terminate in a delicate flagellum. The 2nd joint of the endopod is at least twice as long as the 1st segment and is equal to the length of the last three segments.
The 1st swimming leg possesses the usual three-jointed exopod and a single-jointed endopod. Both basal segments are devoid of spines. The endopod exhibits a rounded swelling about half-way along the length of the external margin and the swelling is crowned with a row of needle-like spines; there are a number of scattered spines on the terminal portion of the joints.
In the 2nd swimming leg basal segments 1 and 2 are devoid of spines. Basal 1 shows a well-marked notch onits outer margin. The exopod consists of three segments and both the 2nd and 3rd are armed with strong spines on their posterior aspects. The endopod consists of two segments and the distal one is armed with spines on the surface and there is a comb of small spines along the external margin, a condition that exactly corresponds with the condition in the male. The end-spine of the exopod is also slightly distorted as in the male.
In the 3rd swimming leg basal 1 bears a number of spines on or near its inner margin, while the outer margin exhibits a clearly-marked indentation. Basal 2 bears a group of small curved spines on the distal portionof its inner border. The terminal spine is distorted and is furnished with widely-spaced teeth of varying size. The number of teeth varies from 17 to 18.
The surface of the segments of the rami of the swimming legs is armed with rows of exceedingly minute spinules, running down the length of the segments.
The 5th leg consists of a basal segment and two free segments of approximately equal length. The proximal segment bears a number of spines on the distal part of the external margin. The distal segment terminates in a sharp spine-like projection around the base of which are a number of sharp spines; a single spine-like seta with a serrated margin, arises from the inner aspect at the junction of the middle and distal thirds.

Synonym (s)
Scolecithrix ctenopus Giesbrecht 1893
Scolecithrix ctenopus T. Scott 1894
Scolecithrix ctenopus Giesbrecht and Schmeil 1898
Scolecithricella ctenopus A. Scott 1909

Common Name (s)
Economic Importance and Threats



• Bay of Bengal (Lat: 15) (Long: 90) INDIA
• INDIA (Record: 28/04/1925)

Literature Source(s)
  • Manakadan, R and Pittie, A (2002) Standardized english and scientific names of the Indian subcontinent-2002 Newsletter for Birdwatchers S. Sridhar 42 p 35
  • Madhupratap, M and Haridas, P (1986) Epipelagic calanoid copepods of the Northern Indian Ocean Copepod 105-117 Available at - NIO, RC Kochi
  • Rosamma, S (1984) Distribution of Calanoid Copepods in the Arabian Sea and Bay of Bengal Mahasagar-Bulletin of the National Institute of Oceanography 17(3) 161-171 Available at - NIO, RC Kochi
  • 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 -

Page last updated on:2009-08-06

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