Disseta palumboi   Giesbrecht  1889 (Copepod)
Organism information awaits expert curation
Class: Maxillopoda

Image copyrights: Biotech Books

Showing the arrangement of the cutaneous pores on the dorsal aspect.

Size (female): length 7.0 mm (male): length 6.44 mm

Female: The proportional lengths of the cephalothorax and abdomen are as 201 to 116, so that the abdomen is contained 1.733 times in the length of the anterior region of the body. The forehead is somewhat truncated at the anterior end and there is a well developed medial swelling from which the two delicate rostral spines arise.
The head is crossed from side to side by a well marked groove forming a neck. The head and 1st thoracic segment are separate, but thoracic segments 4 and 5 are fused. The posterior thoracic margins are rounded and that of the left side projects very slightly further backwards than that on the right.
The abdomen consists of four free segments and the furcal rami.
The genital segment is slightly asymmetrical. There is a swelling on each side in the proximal half of the segment but that on the right side is somewhat less rounded than that on the left and projects slightly further backwards. The posterior borders of the anterior three free segments is fringed with a row of needle-like spines.
The 1st antenna over-reaches the furca by the last three or four segments.
There are three pores on the 1st segment; one on the 6th and one each on the 10th , 11th and 12th segments.
In the 2nd antenna the exopod is somewhat shorter than the endopod. Basal 1 bears no seta; basal 2 bears two setae at its distal end. The exopod consists of 8 segments of which segments 1 to 7 each bear a single seta and segment 8 carries three setae at its distal end and a single seta at about four-fifths of its length. The endopod is slightly longer than the exopod; two unequal setae arise from the outer margin of exopod 1 about half way along its length and at their base a pore opens to the exterior. The inner aspect of both the 1st and 2nd segments are fringed with hairs.
In the mandible, the 2nd basal segment bears 4 setae. The exopod is longer than the endopod and consists of five segments, of which 1-4 each bear a single seta and segment 5 has 3. Endopod 1 bears 4 setae and is also armed with a tuft of small spines; endopod 2 bears ten setae and is similarly armed with delicate spines on its inner aspect, while a row of fine needle-like spines runs across the distal end close to the bases of the setae.
The 1st maxilla has the usual characters. The 1st or biting inner lobe bears 13 spines; lobe 2 has only 1 and lobe 3 bears 3. The 2nd basal segment carries 4 setae; endopod 1 has 3 and the fused segments endopod 2 and 3 bear respectively 4 and 5. The exopod carries 5 small and 6 large setae and between the bases of the 5th and 6th of the latter a pore opens to the exterior.
In the 2nd maxilla the various lobes bear the following number of spines or setae; lobe 1 bears 6, of which one is very small and spine-like; lobes 2, 3 and 4 each bear 3; lobe 5 bears 3 setae and a stout toothed spine, and the distal aspect of the lobe is fringed with delicate hairs. The endopod carries 10 setae.
In the maxilliped, basal 1 bears 1 seta on lobe 1 and 3 setae on each of lobes 2 and 3; lobe 3 is covered with small spines on its distal aspect. Basal 2 bears 3 setae on its anterior margin and 2 distally; the proximal one-third of the anterior margin is fringed with long hairs and a band of spines runs along the segment as far as the base of the third seta. The endopod consists of 5 segments bearing respectively 3, 3, 3, 3 and 4 setae. Endopod 1 to 4 are all armed with needle-like spines.
Male: The proportional lengths of the cephalothorax and abdomen are as 19 to 10, so that the abdomen is contained 1.9 times in the length of the anterior region of the body. The right posterior thoracic margin is more sharply rounded than the left and projects slightly further backwards. As in the female the posterior margins of the abdominal segments are fringed with fine spines and the furcal rami are asymmetrical, that on the left side being larger.
Of the 1st antenna that on the left side is modified to form a grasping organ, whereas that on the right side retains its female character.
In the grasping antenna segments 1 and 2 are fused, but segments 8, 9 and 10 are separate. The knee joint is in the usual situation between the 18th and 19th segments and beyond this joint the distal part of the antenna is composed of four segments, segments 19 and 20, and 21 to 23 respectively being fused.
The 2nd antenna, mouth-parts and swimming legs appear to be similar to those of the female.

Synonym (s)
Disseta palumboi Giesbrecht 1893
Disseta palumboi A. Scott 1909
Disseta atlantica Wolfenden 1911
Disseta palumboi Sars 1925

Common Name (s)
Economic Importance and Threats



• Bay of Bengal (Lat: 15) (Long: 90) INDIA

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
  • 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:2009-08-11

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