Species Card of Copepod
Calanoida ( Order )
    Arietelloidea ( Superfamily )
        Arietellidae ( Family )
            Arietellus ( Genus )
Arietellus mohri  (Bjornberg, 1975)   (F,M)
Syn.: Paraugaptilus mohri Björnberg, 1975 (p.184, figs.F)
Ohtsuka & al., 1994 (p.130, emended description F, figs.F); Guangshan & Honglin, 1997 (p.399, Rem.), Heinrich, 1998 a (p.979, Descr.M, figs.M)
Species Arietellus mohri - Plate 1 of morphological figuresissued from : S. Ohtsuka, G.A. Boxshall & H.S.J. Roe in Bull. nat. Hist. Lond. (Zool.), 1994, 60 (2). [p.132, Fig.16, A].
Female (from Chile): A, genital double-somite (ventral). cd = copulatory duct; cp = copulatory pore; g = gonopore; rd = receptacle duct; o, oviduct; s, spermatothore remnant; sr = seminal receptacle.
Scale bar in mm.
Nota: Geniatl double-somite as long as wide, with anterior pair of gonopores located ventrolaterally anterior to single ventromedial copulatory pore (as in A. plumifer); copulatory ducts much more chitinized and wider than in A. plumifer, slightly asymmetrical, left duct divergent into blind tubule near left genital operculum; seminal receptacle the same shape as in A. plumifer.

Species Arietellus mohri - Plate 2 of morphological figuresissued from : S. Ohtsuka, G.A. Boxshall & H.S.J. Roe in Bull. nat. Hist. Lond. (Zool.), 1994, 60 (2). [p.133, Fig.17, C].
Female: C, P5.
Scale bar in mm.
Nota: P5 with coxa and intercoxal sclerite almost fused, but suture line visible on left side; basis fused with coxa. Right leg with outer basal seta more elongate than left one; endopod represented by small knob with vestigial element at tip; exopod almost fused with basis, but suture visible only on anterior surface, unarmed, round. Left leg with basis with concavity on inner margin; outer basal seta thick, plumose; endopod reduced to low prominence with spinulose seta terminally; exopod almost completely fused with basis, unarmed, round.

Species Arietellus mohri - Plate 3 of morphological figuresissued from : S. Ohtsuka, G.A. Boxshall & H.S.J. Roe in Bull. nat. Hist. Lond. (Zool.), 1994, 60 (2). [p.134, Fig.18, A,B,F,H].
Female: A, Mandibular exopod; B, 5th exopod segment of Md; F, basal spine of Mx2; H, 6th endopod segment of Mxp.
Scales in mm.
Nota: 1st endopod segment of right A2 unarmed, 2nd segment with 2 inner setae of unequal length medially and 5 setae and 1 vestigial setule terminally; exopod 7-segmented (setal formula: 0, 1, 1, 1, 1, 0, 3, respectively). Endopod of Md absent; exopod 5-segmented, 1st to 4th segments each with 1 seta, 5th segment with 1 long seta and vestigial seta. Mx1 with praecoxal arthrite with 5 naked spines and 1 bare orocess; coxal endite with 1 naked, thick seta terminaly, fringed with long setules along ventral margin; coxal epipodite with 8 setae; endopod abent. Mx2 with 1st praecoxal endite with long, bare seta and 1 vestigial element; basal spine (Fig.18,F) with 2 rows of spinules along ventromedial margin. 4th and 5th endopod segments of Mxp, each with only 2 well developed setae and lacking innermost seta, 6th (Fig.18,H) with vestigial seta (a) and short seta (b).

Species Arietellus mohri - Plate 4 of morphological figuresissued from : A.K. Heinrich in Zool. Zh., 1998, 77 (8). [p.980, Figs. 1-10].
Male (from SE Pacif.): 1, habitus (dorsal); 2, forehead (lateral); 3, idem (ventral); 4-5, posterolateral corner of last thoracic segment and urosome (lateral left side; 6, idem (dorsal); 7-8, left A2; 9, Md (part of mandibular palp); 10, spine on Mx1; 11-14, P5.
Scale bars in mm: 1.0 (1-7); 0.100 (8-14).

Species Arietellus mohri - Plate 5 of morphological figuresissued from : T.K.S. Björnberg in Ciencia E Cultura, 1975, 27 (2). [p.185, Figs.45-55]. As Paraugaptilus mohri.
Female (from SE Pacific): 45, habitus (lateral right side); 46, last thoracic segment and urosome (lateral); 47, idem (dorsal); 48, forehead and rostral filaments (lateral); 49, idem and rostral (ventral view); 50, A1; 51, Md (mandibular palp); 52, Md (mandibular blade); 53, Md (masticatory edge); 54, A2; 55, Mx1.
Scale: 1 mm (45, 46, 47, 50; 0.500 (51, 54, 55)

Species Arietellus mohri - Plate 6 of morphological figuresissued from : T.K.S. Björnberg in Ciencia E Cultura, 1975, 27 (2). [p.186, Figs.-56-62]. As Paraugaptilus mohri.
Female: 56, Mx2; 57, Mxp; 58, P1; 59, P2; 60, P3; 61, P4; 62, P5.
All scales: 0.500 mm.

Species Arietellus mohri - Plate 7 of morphological figuresissued from : L. Guangshan & Q. Honglin in Acta Oceanologica Sinica, 16 (3). [p.399, Table 1].
Female : morphological characters in Arietellus mohri.

Nota: Compare with A. unisetosus and A. giesbrechti.
1: Ohtsuka & al. (1994) have reexamined Bjornberg's holotype specimen of Paraugaptilus mohri female and revealed that its belongs to Arietellus instead Paraugaptilus.

NZ: 1

Distribution map of Arietellus mohri by geographical zones
N Chile (31°12'S, 71°57'W), off W Desventuradas Is.
N: 3
(288) F: 6,4; (853) M: 5,65; {F: 6,40; M: 5,65}
Rem.: bathypelagic-abyssopelagic.
For Ohtsuka & al. (1994, p.130) the re-examination of the holotype from Bjornberg (1975) includes several misinterpretations in the mouthparts and legs.
For Heinrich (1998, p.981) the species is similar to A. indicus, but differs from it larger body size, more asymmetrical hooks of the last thoracic segment and in some details of structure in P5.
Last update : 22/10/2015
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Razouls C., Desreumaux N., Kouwenberg J. and de Bovée F., 2005-2021. - Biodiversity of Marine Planktonic Copepods (morphology, geographical distribution and biological data). Sorbonne University, CNRS. Available at http://copepodes.obs-banyuls.fr/en [Accessed September 22, 2021]

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