Species Card of Copepod
Calanoida ( Order )
    Clausocalanoidea ( Superfamily )
        Aetideidae ( Family )
            Gaetanus ( Genus )
Gaetanus minispinus  Tanaka, 1969   (F)
Ref.:
Tanaka, 1969 (p.260, Descr.F, figs.F); Tanaka & Omori, 1970 (p.140); Park, 1975 a (p.10); Bradford & Jillett, 1980 (p.51, figs.F, distribution chart); Markhaseva, 1996 (p.204, figs.F)
Species Gaetanus minispinus - Plate 1 of morphological figuresissued from : J.M. Bradford & J.B. Jillett in Mem. N.Z. Oceanogr. Inst., 86, 1980. [p.54, Fig.35].
Female: A, habitus (dorsal); B, forehead (lateral); C, posterior of thorax (lateral left side); D, lamella on basipod 1 of Mxp.

Nota: The one specimen taken in the south-west Pacific has the lamella of Mxp basipod 1 and the external spine of P1 exopod joint 2 not noticeably different from that of G. kruppi, and A1 did not appear to be as long as described by Tanaka (1969).


Species Gaetanus minispinus - Plate 2 of morphological figuresissued from : O. Tanaka in Publ. Seto Mar. Lab., 1969, XVII (4). [Fig.4].
Female (from China Sea): a, forehead (lateral); b, last thoracic segment and urosome (lateral right side); c, idem (dorsal); d, A2; e, Mx1; f, Mxp (basal segment); g, P1 (exopod); h, P4; i, lamellous process of 1st basal segment of Mxp in Gaetanus kruppi female from Giesbrecht.

Nota Female:
- Proportional lengths of cephalothorax and abdomen 78 : 22.
- Cephalic spine very small.
- Rostrum short, point-like, directed ventrally.
- Head and 1st thoracic segment fused, 4th and 5th fused.
- Posterolateral corners of the last thoracic segment rounded, with a small lateral spine on the distal margin.
- Proportional lengths of urosomites and caudal rami 38 : 17 : 16 : 10 : 19 = 100.
- Genital segment symmetrical, swollen ventrally, the distal margin striated with spinules.
- Caudal rami as long as wide.
- A1 24-segmented (segments 8-9 fused), extends beyond the end of caudal rami by the distal 2 segments.
- A2 exopod about as long as endopod.
- Md with 9 setae on the distal margin of the endopod; cutting edge with 8 teeth and 1 inner marginal seta.
- Mx1: 9 setae on the outer lobe, 11 setae on exopod, 4 + 4+ 6 on endopod, 5 on the 2nd basal segment, 4 on the 3rd inner lobe, 4 on the 2nd inner lobe, 14 on the 1st inner lobe (= arthrite).
- Mx2 robust, with the proximal outer margin of the 1st basal segment swollen endopod with 6 setae, the 5th inner lobe with 2 spines on the anterior distal margin.
- Mxp with 1st basal segment furnished with a lamellous process on the outer margin (which differs in shape from that of G. kruppi.
- P1 exopod 2-segmented (segments 1 and 2 incompletely fused), endopod 1-segmented; the outer marginal spine of the 2nd segment long, reaching the distal margin of the 3rd exopodal segment.
- P2 exopod 3-segmented and endopod 2-segmented; the terminal spine of exopod with 21 teeth.
- P3 and P4 with exopods and endopods 3-segmented each.
- P4 with the 1st basal segment (= coxa) furnished with about 23 bristles on the inner margin.


Species Gaetanus minispinus - Plate 3 of morphological figuresGaetanus minispinus female:
1 - Anterior part of cephalon with frontal spine.
2 - Exopodal segment 1 of A2 without seta; exopodal segment 2 with 1 seta (near distal margin). 2nd internal lobe of Mx1 with 4 setae. Exopod of P1 always with 2 external spines.
3 - Mxp protopodite with lateral plate.
4 - Exopodal segment 2 of A2 with 1 seta.
5 - Spines of last thoracic segment not exceeding the midlength of genital segment. Frontal spine small.


Species Gaetanus minispinus - Plate 4 of morphological figuresissued from : O. Tanaka in Publ. Seto Mar. Lab., 1969, XVII (4). [p.261].
Female A1: Proportional lengths of segments.
-Nota: A1 24-segmented, segments 5-9 fused.

NZ: 4

Distribution map of Gaetanus minispinus by geographical zones
Species Gaetanus minispinus - Distribution map 2Issued from : J.M. Bradford & J.B. Jillett in New Zealand Ocean. Inst. Memoir, 86, 1980. [p.89, Figs.64].
Distribution of several species of Gaetanus in the Tasman Sea and around New Zealand.
Loc:
Japan (Izu), China Seas, Pacif. (equatorial), NW New Zealand .

Type locality: South China Sea.
N: 4
Lg.:
(105) F: 5,5; (113) F: 5,56-5,15; (201) F: 5,4; {F: 5,15-5,56}
Rem.: Meso-bathypelagic.
According to Tanaka (1969, p.261) this species resembles G. kruppi Giesbrecht and G. simplex Brodsky, but distinguished by the small cephalic spine, small lateral spines on the last thoracic segment, and the shape of the lamellous process on the 1st basal segment of Mxp.
Last update : 28/03/2017
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