Species Card of Copepod
Calanoida ( Order )
    Clausocalanoidea ( Superfamily )
        Mesaiokeratidae ( Family )
            Mesaiokeras ( Genus )
Mesaiokeras hurei  Krsinic, 2003   (F,M)
Krsinic, 2003 (p.940, figs.F,M); Vives & Shmeleva, 2007 (p.675, figs.F,M, Rem.)
Species Mesaiokeras hurei - Plate 1 of morphological figuresissued from : F. Krsinic in J. Plankton Res., 2003, 25 (8). [p.941, Fig.1].
Female (from 42°46'02''N, 17°22'02'' E): A-B, habitus (dorsal and lateral, respectively); C, genital double-somite (ventral); D, urosome (lateral); E, A1; F, position of P56; G, forehead (ventral).

Nota: Rostral area rounded without filament. Cephalosome and pedigerous somite 1 fused, 4th and 5th fused, asymmetrical in dorsal view, posterior right margin of 5th pedigerous somite longer than left, covering 1/2 of genital double-somite. Urosome of 4 free somites. Proportional lengths of urosomites and caudal rami 39 : 14 : 16 : 11 : 20 = 100. Ratio of length of prosome to length of urosome (with caudal rami) 3 : 1. Genital area located medioventrally and symmetrical; the opercula are fused, the genital apertures and seminal receptacles are paired; ventro-distal margin of genital double-somite armed with 4 longer processes; some median long, smaller spinules and a tuft of spinumes on the left side. A1 symmetrical, 21-segmented, reaching almost to end of prosome

Species Mesaiokeras hurei - Plate 2 of morphological figuresissued from : F. Krsinic in J. Plankton Res., 2003, 25 (8). [p.942, Fig.2].
Female: A, urosome (dorsal); B, urosome with attached spermatophore (lateral, left side).

Nota: Posterior margins of urosomites 3-4 fringed with very fine spines. Caudal rami asymmetrical, longer than wide, right ramus slightly longer than left.

Species Mesaiokeras hurei - Plate 3 of morphological figuresissued from : F. Krsinic in J. Plankton Res., 2003, 25 (8). [p.943, Fig.3].
Female: A, A2; B, Md; C, Mx1; D, Mx2; E, Mxp.

Nota : A2 : coxa with 1 setule ; basis with 2 setules at inner angle ; exopod 6-segmented with setal armature 1, 4, 1, 1, 1, 1 + 3 terminal setae ; endopod 2-segmented. Md : gnathobase with 8 teeth ; basis with 3 curved setae ; endopod 2-segmented ; exopod 5-segmented, seta on 2nd segment twice as long as on others. Mx1 : praecoxal arthrite bearing 10 elements ; coxal epipodite armed with 7 longer and 2 smaller setae and coxal endite 2 spinulose setae, respectively ; basal endite with 3 setae ; exopod bearing 8 longer and 3 smaller setae ; endopod 3-segmeted, 1st segment bearing 2 setae, 2nd with 2 setae, 3rd with 5 setae. Mx2 : praecoxa with 2 endites, each with 3 setae ; 2 coxal endites each with 2 longer spinulose and 1 shorter seta ; allobasis armed with 4 setae ; endopodal segments with 5 spinulose setae. Mxp : coxa longer than basis ; endopod 6-segmented.

Species Mesaiokeras hurei - Plate 4 of morphological figuresissued from : F. Krsinic in J. Plankton Res., 2003, 25 (8). [p.944, Fig.4].
Female: A-D, P1 to P4; E, P5.

Nota : P5 asymmetrical, left leg 2-segmented, right leg represented by short rounded stump.

Species Mesaiokeras hurei - Plate 5 of morphological figuresissued from : F. Krsinic in J. Plankton Res., 2003, 25 (8). [p.945, Fig.3].
Male: A, habitus (dorsal); B, forehead (ventral); C, urosome (dorsal); D, A1.Nota : Proportional lengths of urosome somites and caudal rami 36 : 15 : 13 : 13 : 13 = 100. A1 non geniculate, right A1 longer than left, reaching almost to end of prosome, comprising 21 free segments. A2 and all of mouthparts identical to those of female.

Species Mesaiokeras hurei - Plate 6 of morphological figuresissued from : F. Krsinic in J. Plankton Res., 2003, 25 (8). [p.947, Fig.6].
Male: A-D, P1 to P4; E, P5.

Nota : Swimming legs P1-P3 identical to those of female ; P4 with outer spine of exopod segment 1 much smaller than in female. Right P5 reduced to a short rounded stump ; left leg uniramous, 5-segmented, longer than prosome, proportional lengths of segment 10 : 28 : 28 : 19 : 15 = 100.

Compl. Ref.:
Belmonte & al., 2013 (p.222, Table 2, abundance vs stations)
NZ: 1

Distribution map of Mesaiokeras hurei by geographical zones
Adriatic Sea (Veliko Jezero, Mljet Is., Croatia), Gulf of Taranto (S Italy)
N: 2
(891) F: 0,345-0,375; M: 0,325-0,35; {F: 0,345-0,375; M: 0,325-0,350}
Rem.: Interior marine lake (depth: 46 m); specimens at 1-11 m above the bottom in suspended detrital material.
According to Krsinic (2003, p.948) both sexes have 21 free antennule segments; this suggests that they may be the most advanced representatives of this genus (also see the antennulary setation patterns), whereas females of most species have 23-segmented antennules, and the most primitive according to Fosshagen (1978) Mesaiokeras hepneri with 24-segmented antennules.
Last update : 30/12/2015
    to add your remark

 Any use of this site for a publication will be mentioned with the following reference :

Razouls C., de Bovée F., Kouwenberg J. et Desreumaux N., 2005-2019. - Diversity and Geographic Distribution of Marine Planktonic Copepods. Sorbonne University, CNRS. Available at http://copepodes.obs-banyuls.fr/en [Accessed February 22, 2019]

© copyright 2005-2019 Sorbonne University, CNRS

CNRS   Observatoire Océanologique de Banyuls sur Mer - Laboratoire Arago
Sorbonne Université


Version française
English version



On the WEB of CNRS


Marine Planktonic Copepods

Marine Planktonic Copepods


Imprimer Contact Accueil Plan du site Accès restreint Retour Une du Labo Imprimer Contact Plan du site Crédits Téléchargez les Plug-Ins