Species Card of Copepod
Calanoida ( Order )
    Arietelloidea ( Superfamily )
        Heterorhabdidae ( Family )
            Heterorhabdus ( Genus )
Heterorhabdus americanus  Park, 2000   (F,M)
Park, 2000 (p.127, figs.F,M, Rem.)
Species Heterorhabdus americanus - Plate 1 of morphological figuresissued from : T. Park in Bull. Scripps Inst. Oceanogr. Univ. California, San Diego, 2000, 31. [p.249, Fig.97].
Female: a, habitus (left side); b, c, urosome (dorsal, left, respectively); d, forehead (left); e, f, genital somite (ventral, left, respectively); g, genital somite from different specimen (left); h, left Mx2 (posterior).

- Cephalosome 46 % length of prosome
- Prosome 70 % length of body and approximately 2.2 times length of urosome.
- Urosome 31 % length of body.
- Length ratios of 4 urosomal somites and left caudal ramus 39.6 : 18.0 : 13.4 : 8.1 : 20.9 = 100.
- Mx2: Posterior subterminal spine of 4th lobe 46 % as long as 2nd saberlike spine; falcate spine of 5th lobe with proximal 56 % of medial margin serrated with spinules; falcate spine of 6th lobe with proximal 70 % of medial margin serrated with spinules.

Species Heterorhabdus americanus - Plate 2 of morphological figuresissued from : T. Park in Bull. Scripps Inst. Oceanogr. Univ. California, San Diego, 2000, 31. [p.250, Fig.98].
Female: a, exopod of P1 (anterior); b, P5 (posterior).

Male: c, P5 (anterior); d, distal end of exopod of right P5 (lateral); e, basipods of P5 (anterior); f, g, basipod of right P5 (anterior, tilted clockwise, respectively); h, i, second exopodalsegment of right P5 (anterior, posterior, respectively); j, exopod of left P5 (anterior).

- Prosome 72 % length of body and about 2.5 times length of urosome.
- Urosome 28 % length of body.
- Caudal rami and setation as in female
- left geniculate A1 similar in morphology to that of H. spinifrons
- All other cephalosomal appendages and P1-P4 as in female

Species Heterorhabdus americanus - Plate 3 of morphological figuresHeterorhabdus americanus female:
1 - See key to species groups of Heterorhabdus: ''abyssalis'' Group (p.90, 114).
2 - Genital somite without a conical projection mediodorsally (Fig.97- a, f).
3 - Laterally, genital somite without a tubercular outgrowth posteriorly on dorsal margin (Fig.97-f).
4 - Laterally, genital operculum far short of reaching posterior end of somite (Fig.97-c).
5 - Laterally, right and left genital flanges symmetrical.
6 - Laterally, genital prominence distinctly separate from ventral wall of somite (Fig.97-f).
7 - Dorsally, as well as ventrally, lateral swellings of genital somite reaching posterior end of somite (Fig.97-b).
8 - Laterally, genital prominence far short of extending to posterior end of somite; genital somite with a low dorsal hump.
9 - Laterally, genital operculum reaching posterior end of genital prominence (Fig.97-c).

Species Heterorhabdus americanus - Plate 4 of morphological figuresHeterorhabdus americanus male:
1 - See key to species groups of Heterorhabdus: ''abyssalis'' Group (p.90, 114).
2 - Basis of left P5 without a well-developed inner lobe (Fig.98-c, e).
3 - Basal inner lobe of right P5 armed with normal bristles (Fig.98-c, e).
4 - 3rd exopodal segment of right P5 with a short terminal lobe, less than 1/3 length of terminal spine (Fig.98-c, d).
5 - Basal lobe of right P5 arising from anteromedial side of segment (Fig.98-a).
6 - 2nd exopodal segment of left P5 with outer spine not borne on a conical process (Fig.98-c, j).
7 - 3rd exopodal segment of right P5 with terminal spine longer than 1/2 length of segment (Fig.98-c).
8 - Anteriorly and when tilted clockwise, basal lobe of right P5 recurved by folding.
9 - Anteriorly, basal lobe of right P5 slightly folded (Fig.98-e).
10 - Basal lobe of right P5 conspicuously inflated distally (Fig.98-e).

Compl. Ref.:
Park & Ferrari, 2009 (p.143, Table 8, biogeography).
NZ: 3

Distribution map of Heterorhabdus americanus by geographical zones
E Pacif. (20° S - 31° N; America westward to 119°W)

Type locality: 16°09'S, 75°42'W.

For Park (2000, p.128) the species is taken in the east Pacific between 20°20' S and 31°38' N and from the west coast of the Americas westward to 118°53' W. This findings seem to indicate that the species is endemic to the coastal area of the eastern tropical Pacific.
N: 1
(824) F: 3,52-3,12; M: 3,36-2,96; {F: 3,12-3,52; M: 2,96-3,36}
Rem.: "Abyssalis" Group.
For Park (2000, p.129) this species is very close to H. cohibilis.
After Park (2000, p.128), the female genital somite is characteristic in having a moderately sigmoid dorsal margin, a strongly ventral margin formed by the genital flange together with the posterior ventral wall and a long genital operculum reaching the junction between the genital flange and the posterior ventral wall.
Last update : 17/10/2017
    to add your remark

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

Razouls C., Desreumaux N., Kouwenberg J. and de Bovée F., 2005-2024. - Biodiversity of Marine Planktonic Copepods (morphology, geographical distribution and biological data). Sorbonne University, CNRS. Available at http://copepodes.obs-banyuls.fr/en [Accessed July 18, 2024]

© copyright 2005-2024 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