Paraeuchaeta weberi   Scott A,  1909 (Copepod)
Organism information awaits expert curation
Taxonomy
Kingdom:Animalia
Phylum:Arthropoda
Class: Maxillopoda
Order:Calanoida
Family:Euchaetidae

Description
Size: length 7.562 mm.

The proportional lengths of the cephalothorax and abdomen are as 81 to 40, the abdomen thus being almost exactly half the length of the anterior region. On the inner side of the last thoracic segment a distinct tuft of short hairs that does not project beyond the posterior thoracic margin. The abdomen consists of four segments.

The length of the abdomen appears to be rather longer in proportion to the cephalothorax . the 2nd and 3rd joints as sparsely clad with long hairs on the ventral aspect. The 2nd furcal seta is two and a half times the length of the others and the accessory seta is much longer than the 2nd seta
The 1st antenna extends to about the middle of the genital segment. Segments 8 and 9 are fused, as also are segments 24 and 25, and the joint between segments 12 and 13 appears to be incomplete. Segments 3, 7, 9 and 14 all bear long setae and segments 2 to 13 are fringed with hair on their posterior surfaces.

The 2nd antenna bears a row of long hairs on the posterior and inner aspect of the 1st basal segment. The endopod bears 6 and 8 setae on the outer and inner lobes respectively of the distal segment. The mandible has a single stout seta on the basal segment of the palp. The endopod is two-jointed, the proximal segment bearing a single seta and the distal having a row of nine on its truncated extremity. The exopod consists of five segments, of which 1 to 4 inclusive each bear a single long seta and the 5th segment bears two smaller ones.

In the maxilla the masticatory lobe bears 4 setae and the endopod bears 7 setae on segments 1 and 2, and 3 setae on segments 3. The exopod carries 11 setae and the outer lobe 10. The proximal three lobes are provided with a tuft of needle-like spinules on the distal part of the posterior aspect.

The maxilliped exhibits one of the characteristics of the genus in the absence of any setae on the anterior margin of the 2nd basal segment at the junction of the proximal and middle-thirds of its length.
The 1st swimming leg possesses a two-jointed basal portion. Basal 1 is fringed with hair on its inner margin; basal 2 is similarly fringed and carries an S-shaped seta at its distal inner angle. The exopod is imperfectly three-jointed; the joint between exopod 1 and 2, though defined, is not complete. Each of the segments bears seta-like marginal spine, that on the 1st segment being very small and delicate. The inner margin of segments 1 and 2 is fringed with hair. Exopod 2 carries a single seta and exopod 3 has three on their respective inner margins. The end-spine is long and seta-like and is serrated inits middle third. The endopod consists of a single segment; the outer margin is produced ina rounded lobe, across which runs a row of needle-like spinules, and two setae arise from the distal end and three from the inner margin.

In the 2nd swimming leg only the inner margin of the 1st basal segment is fringed with hair, that of the 2nd segment being naked. The exopod is three-jointed; exopod 1 bears a short marginal spine and a single inner seta; exopod 2 bears a long marginal spine, that reaches very nearly to the tip of the proximal spine on exopod 3, and a single inner seta; the outer margin of the segment is fringed with hair; exopod 3 bears three marginal spines of which the first is small and reaches only about half-way to the base of the second spine, which is long and reaches to the base of the 3rd spine; the sinus at the base of the 2nd spine is deep and reaches to a line drawn between the base of the 1st marginal spine and the base of the 2nd inner seta; four setae arise from the inner margin of the segment. The end-spine is coarsely serrated, a series of smaller single teeth alternating with the larger ones. The endopod consists of only a single joint; a short spine-like projection arises from the outer margin near the base and a small seta arises from the same margin distally. Two long setae arise from the distal end of the segment and three from its inner border.

In the 3rd swimming leg basal 1 bears an inner seta and the inner border of basal 2 is smooth and devoid of hairs. The exopod is three-jointed and the 1st and 2nd segments each bear a single marginal spine and a single seta on the inner margin. Exopod 3 bears three spines and the interval between the 2nd and 3rd spines is about one and one-quarter times as long as that between the 1st and 2nd. The end-spine is serrated, as in the second leg, with a row of smaller spines between the larger ones. Four setae arise from the inner margin of the 3rd segment. The outer margin of the 2nd segment and the proximal part of the 3rd segment is fringed with hair. The endopod is composed of three segments; endopod 1 and 2 each have a small spine-like projection at the distal outer angle, that on endopod 2 being much the smaller. Each segment bears a single seta. Endopod 3 bears a single small seta on its outer margin. Two long setae distally and 2 on its inner border.

The 4th swimming leg is like the third, but the interval between the marginal spines on the third segment of the exopod is subequal, and the endopod is slightly longer in proportion to the exopod.
There is no trace of any 5th pair of legs.




Synonym (s)
Paraeuchaeta weberi A. Scott, 1909
Paraeuchaeta weberi Sewell, 1913

Common Name (s)
Economic Importance and Threats

Ecology

Biogeography


• INDIA (Record: 23/04/1924)

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:2011-03-14

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