Isias cochinensis - Species Card - Marine Planktonic Copepods

Species Card of Copepod

Calanoida ( Order )	details
Diaptomoidea ( Superfamily )	details
Centropagidae ( Family )	details
Isias ( Genus )	details	List species for this Genus

Isias cochinensis Pillai P. Parameswaran, 1975 (F,M)

Abbreviations or symbols

Ref.:

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List of the studied authors )

Pillai P.P., 1975 a (p.321, Descr. F,M, figs.F,M)

Species Isias cochinensis - Plate 1 of morphological figures

Issued from : P.P. Pillai in Bull. Dept. Mar. Sci. Univ. Cochin, 1975, VII (2). [p.322, Fig. 1].
Female (from Cochin Backwater): a, habitus (dorsal); b, urosome (ventral view); c, urosome (right lateral view); d, urosome (laft lateral view); e, cephalon (lateral view); f, A2; g, Md; h, A1 (segments 1-6); j, P5.
Scales: Single bar: 0.3 mm; double bars: 0.5 mm.

Nota : Cephalon and 1st pedigerous segment fused, 4th and 5th thoracic segments indistinctly fused (line of separation feebly visible laterally).
Cephalon with an eye spot pigmentrd red.
Distinct mid-dorsal hump present at junction of cephalon and 1st thoracic segment.
Posterior margin of thoracic segment 5 produced on either side into distinctly rounded processes, tip reaching to ¼ length of genital segment.
Prosome : Urosome = 1.95 : 1.
Urosome 3-segmented, proportional lengths with caudal rami 34 : 28 : 16 : 22 = 100.
Genital segment longest with irregular lateral margins ; ventral plate of genital segment extensive an dits lateral margins visible in dorsal view ; ventrally genital segment situated on a genital boss, which is laterally and posteriorly protected by a curved plate ; left margin of ventral plate with 3 spines and right margin with 4 spines directed posteriad ; in lateral view, median spines on posterior margin of ventral plate appears as prominent structure directed posteriad.
Urosomal segment 2 longer than broad.
Anal segment as long as broad.
Caudal rami nearly 3 times as long as broad but asymmetrical, left ramus being slightly broader ; on outer margin proximal to the point of origin of 5th apical seta each ramus is armed with a row of 3 to 4 needle-like spines.
A1 23-segmented, reaching to middle of urosomal segment 2 ; segments 8 and 9 fused, a distinct spine arising from disto-dorsal margin of 1st segment.
Exopod of A2 distinctly 7-segmented with the setal formula 1 : 3 : 1 : 1 : 1 : 1 : 0 : 3 : 0.
Md with apical and subapical teeth well developed and acute, 4 median teeth bluntly pointed and basal tooth enlarged and with few needle-shaped spinules ventrally.

Species Isias cochinensis - Plate 2 of morphological figures

Issued from : P.P. Pillai in Bull. Dept. Mar. Sci. Univ. Cochin, 1975, VII (2). [p.322, Fig. 1].
Male: k, habitus (dorsal); l, urosome (dorsal); m, cephalon (lateral); n, A1 (geniculate part); p, P5.
o, P5 from copepodite 5 male.
Scales: Single bar: 0.3 mm; double bars: 0.5 mm.

Nota : Lateral margins of thoracic segment 5 not projected as in female.
Prosome : Urosome = 1.50 : 1.
Urosome 5-segmented, proportional lengths with caudal rami 13 : 20 : 21 : 12 : 11 : 23 = 100.
Urosomal segment 2 with a well developed blunt projection on its right distal corner, directed latero-posteriad.
Right A1 geniculate, 22-segmented, reaching to urosomal segment 3, dorsal margins of segments 15 and 16 carry spines ; segment 17 with a dorsal proximal spine serrated at its inner margin and curved at its tip ; segment 18 and proximal half of fusion segment 19-20 with denticulated plate on their dorsal margin ; a small spine present on the proximal corner of segment 19.
P5 asymmetrical ; each leg consists of 2-segmented exopod and rudimentary endopod. Right leg : basis with a rounded finger-like process carrying a small spine at apex the endopod ; exopodite 1 with a disto-lateral spine ; exopodite 2 with 3 outer lateral spines and a long terminal spine, there is a distinct peg-like projection at the inner distal margin, and the inner margin emarginated. Left leg : basis with a semi-conical endopod, rounded at tip and with a subterminal notch carrying a small spinule ; exopodite 1 elongated and with a disto-lateral spine ; exopodite 2 with 2 outer marginal spines and sub-terminally at outer distal corner with 2 long spines of which inner one is warty ; inner distal corner of segment produced as a finger-like projection, apex of which biloded.

Issued from : P.P. Pillai in Bull. Dept. Mar. Sci. Univ. Cochin, 1975, VII (2). [p.326, Table 1].
Characters of certain appendages.
Ri = endopod; Re = exopod; Roman numerals = spines; Arabic numerals = setae.

NZ:

Distribution map of Isias cochinensis by geographical zones

Distribution map of Isias cochinensis for the Zone Indian Ocean

Loc:

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Geographical glossary )

India (Cochin Backwater)

Lg.:

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References of the authors concerning dimensions )

(1155) F: 1,19-1,33; M: 1,18-1,27; {F: 1,19-1,33; M: 1,18-1,27}

Last update : 05/02/2015


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