Stephos projectus - Species Card - Marine Planktonic Copepods

Species Card of Copepod

Calanoida ( Order )	details
Clausocalanoidea ( Superfamily )	details
Stephidae ( Family )	details
Stephos ( Genus )	details	List species for this Genus

Stephos projectus Moon, Youn & Venmathi Maran, 2015 (F,M)

Abbreviations or symbols

Ref.:

(

List of the studied authors )

S.Y. Moon & al., 2015 (p.31, Descr.F, M, figs.F, M, Rem.)

Species Stephos projectus - Plate 1 of morphological figures

Issued from : S.Y. Moon, S.-H. Youn & B.A. Venmathi Maran in ZooKeys, 2015, 495. [p.30, Fig.5].
Female (34°29'13''N, 127°29'12''E): A-B, habitus (dorsal) with spermatophore; B, habitus (lateral); C, 5th pedigerous somite and urosome (dorsal); D, urosome (lateral); E, genital double-somite (ventral); F, 2nd urosomal somite to caudal rami (ventral).
Scale bars: 200 µm (A, B); 100 µm (C, D); 50 µm (E, F).

Prosome-urosome ratio 1.83: 1.
- Length ratio of urosomites as 51.1 : 18.9 : 17.3 : 12.7 = 100.
- Caudal rami with 6 setae, symmetrical, about 1.63 times longer than wide, with 4 transverse rows of spinules on ventral surface; caudal seta I lacking; seta II reduced; seta VII displaced to medial margin.

Species Stephos projectus - Plate 2 of morphological figures

Issued from : S.Y. Moon, S.-H. Youn & B.A. Venmathi Maran in ZooKeys, 2015, 495. [p.34, Fig.6].
Female: A, A1; B, A2; C, Md; D, Mx1; E, Mx2; F, Mxp.
Scale bars: 50 µm.

Nota: A1 similar to S. geojinensis except for not extending beyond distal margin of 5th pedigerous somite.
- A2 similar to S. geojinensis except for presence of 2 transverse rows of spinules (instead of tiny serrated process plus spinule) on lateral margin of distal segment of endopod.
- Md similar to S. geojinensis except for: 1- coxal gnathobase with straight row of moderately incised teeth; 2- outer margin of proximal segment of exopod with row of setules; 3- distal segment of endopod with transverse row of spinules.
- Mx1 and Mx2 similar to S. geojinensis except for presence of 1 additional seta on basal endite of Mx2.
- Mxp differing from S. geojinensis in presence of additional rows of tiny spinules on syncoxa.

Species Stephos projectus - Plate 3 of morphological figures

Issued from : S.Y. Moon, S.-H. Youn & B.A. Venmathi Maran in ZooKeys, 2015, 495. [p.35, Fig.7].
Female: A, P1; B, P2; C, P3; D, P4; E, P5.
Scale bars: 50 µm.

Nota: P1 to P4 with armature formula as in S. geojinensis but with outer spine on 2nd exopodal segment of P1 transformed into seta.
P5 symmetrical, uniramous, 3-segmented with proximal segment fused to intercoxal sclerite; 2nd segment similar to S. geojinensis but shorter (1.72 times longer than wide); distal segment with 1 seta instead of spine on lateral margin, and with spinulation on terminal spine not so coarse.

Species Stephos projectus - Plate 4 of morphological figures

Issued from : S.Y. Moon, S.-H. Youn & B.A. Venmathi Maran in ZooKeys, 2015, 495. [p.36, Fig.8].
Male: A-B, habitus (dorsal and lateral, respectively); C, A1; D-E, P5 (different views)

Nota: Prosome-urosome ratio 1.87:1.
- Length ratio of urosomites as 23.7 : 25.6 : 22.6 : 18.6 : 9.5 = 1000.
-Caudal rami similar to those of female.
A1 similar to S. geojinensis escept for not extending beyond distal margin of 5th pedigerous somite and for failure to express 1 aesthetasc on ancestral segments VI, VIII, composite X-XI, XX. In addition, the composite segment I-II displays 4 setae (vs. 3 in S. geojinensis).
- A2, Md, Mx1, Mx2, Mxp and P1 to P4 similar to female.
- P5 strongly asymmetrical, uniramous and filiform. Left leg 5-segmented; segments 3 and 4 each with rounded outgrowth on medial margin, outgrowth on segment 3 more slender and crowned with hyaline frill, that on segment 4 with ridged plate terminally; 4th segment with additional short conical outgrowth and longituninal row of spinules; distal segment short, rounded, with 4 long hyaline lamellae on distal margin and patch of short spinumles on posterior surface. Right leg 4-segmented; segment 3 elongate, straight and slender except for blunt triangular process proximally on lateral margin; 4th segment sickle-shaped with rouned tip; 4 rounded outgrowths along inner margin and single outgrowth suntermonally on outer margin of segment.

NZ:

Distribution map of Stephos projectus by geographical zones

Distribution map of Stephos projectus for the Zone China Seas, Vietnam

Loc:

(

Geographical glossary )

S Korea (Bongyoungri, Naro Island).

Type locality: ± 34°29'13'N, 127°29'12''E.

Nota from Brylinski & Courcot (2019, p.10): Collected in the stagnant water flooding the burrows excavated by ocypodid crabs.

Lg.:

(

References of the authors concerning dimensions )

(1179) F: 1,47-1,61; M: 0,86-0,96; {F: 1,47-1,61; M: 0,86-0,96}

Rem.:

For S.Y. Moon & al. (2015, p.33) the species falls within the ''group III'' (after Bradford-Grieve, 1999 a), characterized by a 4-segmented right male P5 combined with a left leg in which the 4th segment is swollen.
S. projectus and S. geojinensis are easily differentiated based on the ornamentation of both the female genital double-somite and genital operculum; the morphology of the distal segment of the male right P5; the presence/absence of a tiny pointed process on the distomedial angle of 2nd segment of female P5; and the condition (seta or spine) of the lateral armature element on distal segment of female P5, among other features.
Among the species belonging to ''group III'' , only two of them, S. hastatus and S. robustus, share with S. projectus an asymmetrical female genital double-somite.

Last update : 29/04/2019


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