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Marine Planktonic Copepods
Stephos grievae  Krsinic, 2015   (F,M)
Taxonomy
Order Calanoida
Superfamily Clausocalanoidea
Family Stephidae

References

Krsinic, 2015 (p.1, Descr. F, M, figs. F, M, Rem.)

Figures

Plate 1 Issued from : F. Krsinic in Mar. Biodiv. Rec., 2015, 8. [p.3, Fig.1].
Female (from 42°47'42.2''N, 17.5°23'22.3''E): A-B, habitus (dorsal and lateral, respectively); C, rostral area (ventral).

Nota: ratio of prosome and urosome as 2.9 : 1.
- Rostral area, with 2 sensillae medially, rostrum represented by rounded knob.
- Urosome 4 free somites; proportional lengths of urosomites and caudal rami 37.4 : 18.6 : 17 : 13.5 : 13.5 = 100.
- Caudal rami symmetrical, 1.25 times longer than wide; ramus with 4 terminal setae corresponding to setae III-VI, seta VII small, pinnate, setae I and II absent
Plate 2 Issued from : F. Krsinic in Mar. Biodiv. Rec., 2015, 8. [p.4, Fig.2].
Female: A, A1 segments 1-15; B, A1 segments 16-24; C, urosome (dorsal); D, genital double-somite (ventral).

Nota: Genital double-somite about as long as wide, symmetrical, with proximolateral margins produced in dorsal aspect. External genital area symmetrical in venytral view, paired egg-laying duct, paired gonopores situated medially near posterior edge, covered by single operculum.
- A1 symmetrical, 24-segmented, reaching almost to end of 3rd urosomite.
Plate 3 Issued from : F. Krsinic in Mar. Biodiv. Rec., 2015, 8. [p.5, Fig.3].
Female: A, A2; B, Md; C, Mx1; D, Mxp; E, Mx2.

Nota: A2 with exopod (7-seggmented) longer than endopod (2-segmented).
- Md gnathobase cutting edge with isolated unicuspid tooth, 8 heterogeneous teeth and 1 dorsal spinulose seta. Endopod 2-segmented (1st segment with 4 unequal setae and terminal segment truncate bearing 11 setae). Exopod 5-segmented (setal formula: 1, 1, 1, 1, 2).
Mx1 praecoxal arthrite bearing 9 stout marginal spines and 4 elements on posterior surface; coxal epipodite with 9 and coxal endite with 4 setae; proximal basal endite with 3 setae, distal basal endite with 5 setae, basal exite unarmed; exopod bearing 11 setae; endopod articulated to basis, indistinctly 3-segmented, with setal formula 3, 4, 7.
- Mx2 praecoxal endites with 6 and 3 setae, respectively; coxal endites each with 3 setae; allobasis with proximal endite powerfully developed with 3 setae, 1 stouter than rest; endopod 3-segmented, with setal formula 1, 1, 4.
- Mxp praecoxal endite with 1 seta and row of spinules; syncoxal endites, setal formula 2, 3, 3on medial margin, distal seta thorn-like; distal margin with row of spinules; basis with longitudinal row of spinules and with 3 setae, free endopod 6-segmented, armature formula 2, 4, 4, 3, 3+1, 4.
Plate 4 Issued from : F. Krsinic in Mar. Biodiv., 2015, 8. [p.6, Fig.4].
Female: A, P1; B, P2; C, P3; D, P4; E, P5.

Nota: P5 symmetrical, uniramous, 3-segmented, proximal segment separated fom intercoxal sclerite; 3rd segment very long, armed with setules distally along both margin; distal segment armed with single small spine on anterior surface and spiniform process laterally.
Plate 5 Issued from : F. Krsinic in Mar. Biodiv. Rec., 2015, 8. [p.2].
Female and Male : Armature formula in swimming legs P1 to P4.
Plate 6 Issued from : F. Krsinic in Mar. Biodiv. Rec., 2015, 8. [p.7, Fig.5].
Male: A-B, habitus (dorsal and lateral, respectively); C, urosome (dorsal).Nota: Rostral area as in female.
- Prosome: urosome ratio = 2.85: 1.
- Urosome 5 somites; proportional lengths of urosomites 30 : 16.5 : 20 : 18.5 : 15 = 100.
- genital somite slightly asymmetrical viewved dorsally, wider than long; genital aperture located on left side.
Caudal rami as in female.
Armature of A2 and swimming legs P1 to P4 as in female.
Plate 7 Issued from : F. Krsinic in Mar. Biodiv. Rec., 2015, 8. [p.8, Fig.6].
Male: A, A1 segments 1-15; B, A1 segments 16-24; C, right P5; D, E, F, left P5 (F: segments 4 and 5).
-P5 uniramous and asymmetrically. Right leg 4-segmented and very long; esgment 2 (basis) longer than coxa, segment 4 very elongate, distal part is more robust than proximal, hook-like distally with thickened knee-shaped projection and inner margin with small denticles. left leg 5-segmented, segments unarmed, segment 2 (basis) elongate and robust, segments 3 and 4 shorter and of similar length, segment 5 crescent -shaped, longer than segment 2, articulated to segment 4 at approximately 1/4 of length of segment, shorter part in form of heavy, tapering processes, while longer part forms a club-shaped curved extension.

Distribution

NZ: 1

Distribution map of Stephos grievae by geographical zones


Localisations

Lenga Pit, Mljet Island (S Adriatic)

Type locality: 42° 47' 42.2'' N, 17.5° 23' 22.3'' E.

Quotations

N: 1

Dimensions (mm)

(1196)* F: 0, 60-0,67; M: 0,55-0,62.
* : excluding caudal rami.

Remarks

Lenga Pit (Mljet Island) is about 100 m from the shoreline, there is a small 9 m deep lake at the end of the cave (Salinity in the water column below depths of 3 m is between 21.00 and 39.00, temperature approximately 15.5°C.
For Krsinic (2015, p.5) the species with male P5 is typical of species group IV (see Bradford-Grieve, 1999).
Last update : 12/05/2016

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