Species Card of Copepod
Calanoida ( Order )
    Clausocalanoidea ( Superfamily )
        Euchaetidae ( Family )
            Paraeuchaeta ( Genus )
Paraeuchaeta confusa  Tanaka, 1958   (F,M)
Syn.: Pareuchaeta confusa Tanaka, 1958 (p.344, figs.F,M); Tanaka & Omori, 1968 (p.232, figs.F); Mauchline, 1998 (tab.42);
? P. confusa : Heptner, 1971 (p.81, figs.F);
Euchaeta confusa : Park, 1975 c (p.13, figs.F,M)
Bradford & al., 1983 (p.20); Park, 1994 (p.322, 327, biogéo.); Park, 1995 (p.56, Rem.F,M, figs.F,M)
Species Paraeuchaeta confusa - Plate 1 of morphological figuresissued from : T. Park in Bull. Scripps Inst. Oceanogr. Univ. California, San Diego, 1995, 29. [p.159, Fig.49].
Female: a, forehead (left side); b, urosome (left); c, genital somite (left); d, e, f, outer lobe of Mx1 (showing individual variations in size of proximal setae); g, P1 (anterior); h, P2 (anterior).
Nota: Laterally, rostrum large, spiniform, its anterior margin beginning some distance from suprafrontal sensilla and straight, forming an angle of about 20° with anterodorsal margin of forehead.
Urosome elongate.
Dorsal wall of genital somite smoothlu curved. Ventral margin of genital flange slightly bulging and strongly oblique in a posteroventral direction. Posterior edge of genital field produced into a conspicuous lobe, ventral margin of which relatively long, straight and nearly perpendicular to distal edge of genital flange. Posterior margin of genital prominence strongly convex, with an irregular outline, alittle shorter than posterior ventral wall of somite, which is also bulged out; they meet at a sharp angle. Anterior margin of prominence nearly straight or slightly bulging out with a small inconspicuous ridge at middle.
Cephalosomal appendages including Mx1 similat to those of P. malayensis except that 2 small proximal setae of Mx1 outer lobe extending laterad, insyead of pointing proximad, and in certain individuals, one of both of the small proximal setae are much reduced in size.
In P1 exopod, outer spine of 1st segment very small; that of 2nd segment short of reaching base of following outer spine.
In P2 exopod, 2nd outer spine reaching middle of following outer spine and a little longer than 4th oiter spine; marginal lobe bearing 4th outer spine separated from segment by a relatively deep incision.

Male: i, forehead (left); j, last pedigerous and genital somites (left); k, exopod of P1 (anterior); l, exopod of P2 (anterior); m, distal exopodal segments of left 5th leg (anterior, tilted counterclockwise); n, idem (lateral, tilted clockwise).

Species Paraeuchaeta confusa - Plate 2 of morphological figuresissued from : O. Tanaka in Publs Seto Mar. Biol. Lab., 1958, VI (3). [p.345, Fig.70] As Pareuchaeta confusa.
Female: a, habitus (dorsal); b, forehead (lateral left side); c, last thoracic segment and genital somite (lateral left side); d, genital somite (ventral); e, exopod of P2.
Nota: The urosome segments and furca are in the proportional lengths as 41:24:21:3:11 = 100. A1 extends to the lateral corner of the last thoracic segment.

Male: f, forehead (lateral left side); g, last thoracic segment and genital somite (lateral left side); h, P5; i, terminal segments of left P5.
Nota: The urosome segments and furca are in the proportional lengths as 24:32:29:21:5:8 = 100.

Species Paraeuchaeta confusa - Plate 3 of morphological figuresissued from : O. Tanaka & M. Omori in Publs Seto Mar. Biol. Lab., 1968, XVI (4). [p.233, Fig.8]. As Pareuchaeta confusa.
Female: A, genital complex (ventral); B, genital somite (lateral left side); C, biting edge of Md; D, Mx1; E, P1; F, P2.
Nota: The urosome segments and furca are in the proportional lengths as 44:22:22:3:9 = 100. Prosome and urosome are in the proportional lengths as 73 to 27.

Species Paraeuchaeta confusa - Plate 4 of morphological figuresissued from : M.V. Heptner in Trudy. Inst. Okeanol., 1971, 92. [p.82, Fig.3]. As Pareuchaeta confusa. With doubt.
Female (from Kuril-Kamchatka Trench).
Body length: 7.85-8.0 mm.
Formula of the exopod of P1 spines on the last two segments, successively : Aa ≈ 1/10 Ab; Bb < BC (Bb ≈ 4/5 BC); Cc > BC. Variant: Aa ≈ 1.5 AB; Bb ≈ 1/2 BC. P2: Aa > AB (AC = AB + 1/3 Bb); Bb < BC (Bb ≈ 2/3 BC); Cc < CD (Cc ≈ 4/5 CD) Variant: Aa = AB; Aa < AB (Aa ≈ 9/10 AB); Bb = Bc. [cf. legend in drawings of Heptner, 1971, for Pareuchaeta rubra]

Species Paraeuchaeta confusa - Plate 5 of morphological figuresissued from : T. Park in Smiths. Contr. Zool., 1975, 196. [p.14, Fig.11]. As Euchaeta confusa.
Female (W Caribbean Sea): a, forehead (lateral); b-d, genital segment (left side, right side and dorsal, respectively); e, genital field; f, outer lobe of Mx1; g, P1 (anterior); h, P2 (anterior).

Male: i, forehead (lateral); j, exopod of P1 (anterior); k, exopod of P2 (anterior); l, exopod of left P5 (medial); m, same (anterior).

Nota: Te species was collected in tows down to depths of 1000 and 2000 m.. These findings are the first record of the species in the Atlantic Ocean.

Species Paraeuchaeta confusa - Plate 6 of morphological figuresParaeuchaeta confusa Female:
1 - See key to species Groups and independent species of Paraeuchaeta (p.30): malayensis species Group.
2 - Outer spine of 2nd exopodal segment (or the 2nd of the first 2 exopodal segments forming a proximal, compound segment) of P1 normally developed (Fig.49-g).
3 - Outer lobe of Mx1 with 7 long setae in addition to 2 short, unequal-size setae proximally (Fig.49-d, e).
4 - Genital somite without a conical process on left side close to anterior base of genital prominence (Fig.49-c).
5 - Dorsally and ventrally, genital somite symmetrical.
6 - Laterally, genital flange with normal posterior lobe (Fig.49-c).
7 - Laterally, genital somite with more or less smooth dorsal margin (Fig.49-c).
8 - Laterally, genital prominence with conspicuously bulging posterior margin (Fig.49-c).
9 - Laterally, genital prominence with irregular posterior margin (Fig.49-c).

Compl. Ref.:
Suarez-Morales & Gasca, 1998 a (p.109); Razouls & al., 2000 (p.343, Appendix)
NZ: 5 + 1 doubtful

Distribution map of Paraeuchaeta confusa by geographical zones
Species Paraeuchaeta confusa - Distribution map 3
Chart of 1996
Species Paraeuchaeta confusa - Distribution map 4issued from : T. Park in Hydrobiologia 292/293, 1994. [Fig. 3, p.327]. Geographical distribution of Paraeuchaeta confusa (circle).
Antarct. (W Peninsula) (in Yamanaka, 1976), off Chile, China Seas (East China Sea), Japan (Sagami, Suruga), ? Kuril-Kamchatka Trench, W Caribbean Sea (Bartlett Deep)
N: 6
(3) F: 7,3-6,8; M: 6,9-6,5; (19) F: 6,5-7,08; M: 5,83-5,91; (63) F: 7,93-6,9; (99) F: 7,6-6,6; M: 7-6; {F: 6,50-7,93; M: 5,83-7,00}
Rem.: Sampling depth (Sub-Antarct.) : 2000-3000 m.
Park (1995) doubts the identification of Heptner (1971) because the differences in the lateral aspect of the female genital somite.
According to Tanaka (1958, p.346) the specimens from Japan resemble closely P. malayensis, P. propinqua and P. polaris.
Park (1995, p.56) found this species off the Pacific coast of Japan and in the East China Sea between 25°N and 35°N. After Park, the Caribbean specimens previously reported on are identical in all morphological features th those from the western Pacific, the type locality.
Last update : 27/01/2015
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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 June 25, 2024]

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