Oithona bjornbergae - Species Card - Marine Planktonic Copepods

Species Card of Copepod

Cyclopoida ( Order )	details
Oithonidae ( Family )	details
Oithona ( Genus )	details	List species for this Genus

Oithona bjornbergae Ferrari & Bowman, 1980 (F,M)

Abbreviations or symbols

Ref.:

(

List of the studied authors )

Ferrari & Bowman, 1980 (p.9, figs.F,M); Reid, 1985 a (p.27, fig.M, Rem.); Rocha, 1985 (p.214, figs.F,M); Bradford-Grieve & al., 1999 (p.886, 966, figs.F)

Species Oithona bjornbergae - Plate 1 of morphological figures

issued from : F.D. Ferrari & T.E. Bowman in Smiths. Contr. Zool., 1980, 312. [p.8, Fig.3].
Female (from mouth of Rio Araca Granda, Brazil): a, habitus (lateral left side); b, forehead (dorsal); c, urosome (lateral left side); d, urosomal segments 2-4 (ventral); e, caudal ramus (dorsal); f, A1; g, A2; h, Mdi, Mx1; j, Mx2; k, Mxp; l, P1; m, P2; n, P3; o, P4.
Nota: Rostrum absent. Urosomal segments 2-4 fringed on posterolateral margin. Urosomal segments 2-3 with one transverse row of minute hairs on ventral surface near posterior margin, urosomal segment 4 with 2 rows. Caudal ramus length 2-times width. Knob near genital opening armed with a small spine

issued from : F.D. Ferrari & T.E. Bowman in Smiths. Contr. Zool., 1980, 312. [p.9, Fig.4].
Male: a, habitus (lateral left side); b, posterior paortion of cephalosome (lateral right side); c, urosome (lateral left side); d, urosomal segments 3-6 and caudal rami (ventral); e, A1.

Nota:
- Head rounded dorsally, laterally slightly more acuminate than female.
- Cephalosome with triangular extension posteriorly toward ventral margin.
- Cephalosome with few unorganized sensor hairs and pores (differ in structure from those of \"pore signature\" in most oithonids).
- Urosomal segments 3-4 with a transverse row of minute hairs on ventral surface near posterior margin, urosomal segment 5 with 2 rows.
- Genital flap with 1 large seta, below it several tiny toothlike spines.

issued from : C.E.F. Rocha in Rev. Hydrobiol. trop., 1985, 18 (3). [p.215, Figs.1-6].
Female (from Manaus, Brazil): 1, caudal ramus; 2, Mx1; 3, exopod of P3 (external and apical edges); 4, exopod of P4 (external and apical edges); 5, endopod of P4.

Male: 6, anal somite and caudal rami (dorsal).

Scale bars = 0.050 mm.
Arrows indicate derails absent in the original description drawings.

Nota Female:
- Caudal rami 2.2-2.4 times longer than wide and as long as anal somite; apical median setae thickened and densely plumose, ending in flexible filament; dorsal seta little shorter than outer median apical seta and twice length of innermost apical seta; outer apical seta about a half length of inner one.
- A1 reaching posterior border of thoracic segment 2.
- Md endopod with 4 setae.
- Mx1 without endopodite and with 3 setae (the median one smootrh) on basis.
- Number of spines on esternal edges of exopod P1 to P4: 1.1.2, 1.1.2, 0.1.1, 0.0.1.
- Exopodal segment 1 of P3 (fig.3) and exopodal segments 1 and 2 of P4 (fig.4) with spinules replacing external, articulated spines.
- Endopod of P4 with 3 modigied setae on internal margin (fig.5)

Nota Male:
- Cephalosome without lateral flap.
- Caudal ramus twice longer than wide and with median apical setae and inner apical seta thickened .
- All setae of endopodal segment of P4 plumose.

NZ:

Distribution map of Oithona bjornbergae by geographical zones

Loc:

(

Geographical glossary )

Brazil (Mouth of Rio Acara Granda, Grande River), Amazon region, Guyana ( St. Jean pond)
Type locality: 01°27.8' S, 48°29.2' W.

Lg.:

(

References of the authors concerning dimensions )

(624) F: 0,510-0,440; M: 0,480-0,410; (870) F: 0,465-0,500; M: 0,430-0,450; {F: 0,44-0,51; M: 0,41-0,48}

Rem.:

Brackish, epipelagic.
After Rocha (1985, p.214), The specimenn examined shows minor differences from the original description (Ferrari & Bowman, 1980): in the length ratio of the caudal setae, aspect of the terminal end of the caudal median setae and size of the glange on the distal part of the inner proximal seta of the endopodal segment 2 of P4.
This species inhabits freshwater areas subject to tidal influence; Temperature range: 27.0 to 30.8 °C, ph from 6.0 to 7.0.

Last update : 01/12/2017


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