Racovitzanus levis - Species Card - Marine Planktonic Copepods

Racovitzanus levis Tanaka, 1961 (F,M)

Taxonomy

Order Calanoida

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Superfamily Clausocalanoidea

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Family Scolecitrichidae

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Genus Racovitzanus

details list species for this Genus

Abbreviations or symbols

References

List of the studied authors

Tanaka, 1961 a (p.185, figs.F,M); Grice & Hulsemann, 1965 (p.224, 239, figs.M, Rem.); Park, 1983 (p.171); Bradford & al., 1983 (p.91); Vives & Shmeleva, 2007 (p.818, figs.F,M, Rem.)

Figures

Plate 1 issued from : G.D. Grice & K. Hulsemann in J. Zool., 1965, 146. [p.238, Fig.13, l-m].
Male (from NE Atlantic, station not specified): l, P5; m, terminal segment of exopod of right P5.

Nota: The female specimens agree with Tanaka's (1961, p.186) description but the males differ in details of the terminal segment of the right exopod of P5; this segment has 3 spines and several teeth.

Species Racovitzanus levis - Plate 2 of morphological figures

Plate 2 issued from : O. Tanaka in Publ. Seto Mar. Biol. Lab., 1961, IX (1). [p.186, Fig.125].
Female (Japan: Suruga Bay): a, habitus (dorsal); b, forehead (lateral); c, last thoracic segment and urosome (lateral, left side); d, rostrum (frontal view); e, A1; f, Mx2; g, Mxp; h, P1; i, P2; j, P3.
Nota :
- Cephalothorax and abdomen in the proportional lengths 72 : 28.
- Head and 1st pediger fused, pediger segments 4 and 5 incompletely fused.
- Last thoracic segment with lateral distal corner bluntly produced.
- Rostrum sausage-shaped, slightly bifurcate at the distal end to which 2 small spines attached.
- Urosome 4-segmented ; segments and caudal rami in the proportional lengths 26 : 16 : 14 : 21 : 9 = 100.
- Caudal rami asymmetrical, left side much larger than the right (9 : 7) ; 2nd inner caudal seta of the left side much longer than the total length of the body and curved inwardly almost at right angle at the proximal one fifth of the seta.
- A1 20-segmented (segments 8-9-10 fused, 21-22-23 fused, 24-25 fused) , extends to the distal end of the 3rd thoracic segment ; a long aesthetascs on the segments 2, 3, 12, 14, 19 and 25.
- Endopod of A2 about as long as the exopod.
- Mx2 with 4 long vermiform and 3 small sheaf-like filaments on the terminal section.
- Mxp with a small stalked seta on the middle of the 1st basal segment.
- Terminal spine of the exopod of P3 with 12 teeth, and that of P4 with 17 teeth. P4 without inner marginal seta on the 1st basal segment.
- P5 completely absent.

Male (from Japan: Sagami Bay): k, forehead (lateral); l, last thoracic segment and urosome (dorsal); m, P5.
Nota :
- Cephalothorax and urosome in the proportional lengths 75 : 25.
- Urosomal segments and caudal rami in the proportional lengths 21 : 19 : 19 : 26 : 2 : 13 = 100.
- A1 20-segmented (segments 8-9-10 fused, 11-12-13 fused, 24-25 fused), extends to the distal end of the thorax ; 1st segment furnished with a row of long hairs on the posterior margin.
- A2 with endopod longer and wider than the exopod.
- Mouth appendages less developed.
- P1 to P4 as in female ; terminal spine of the exopod of P2 with 19 teeth.
- P5 resembles that of the male of Scaphocalanus. It extends to the distal end of the caudal rami when reflexed ; Endopod of right leg long, slightly exceeds the distal margin of the 1st segment of the exopod of the left leg ; endopod of the left leg longer than the 3-segmented exopod.

Plate 3 issued from : O. Tanaka in Publ. Seto Mar. Biol. Lab., 1961, IX (1). [p.187]
Female: Proportional lengths of the segments of A1.

Plate 4 issued from : O. Tanaka in Publ. Seto Mar. Biol. Lab., 1961, IX (1). [p.188]
Male: Proportional lengths of the segments of A1.

Complementary References

List of the studied authors

Furuhashi, 1966 a (p.295, vertical distribution in Oyashio region, Table 6); Grice & Hulsemann, 1967 (p.16); Park, 1970 (p.476); Roe, 1972 (p.277, tabl.1, tabl.2); Harding, 1974 (p.141, tab. 3, gut contents); Deevey & Brooks, 1977 (p.256, tab.2, Station "S"); Vives, 1982 (p.292); Guangshan & Honglin, 1984 (p.118, tab., Rem.: p.165); Lozano Soldevilla & al., 1988 (p.58); Shih & Young, 1995 (p.73); Kuriyama & Nishida, 2006 (p.299: Tab.II, fig. 10, vertical distribution); Williamson & McGowan, 2010 (p.273, Table III, Pacific central gyres: N & S); Bonecker & a., 2014 (p.445, Table II: frequency, horizontal & vertical distributions, Table IV: new geographical record); Dias & al., 2019 (p.1, Table II, IV, occurrrence, vertical distribution, Rem.: p.13).

Distribution

NZ: 7

Distribution map of Racovitzanus levis by geographical zones

Distribution map of Racovitzanus levis for the Zone Indian Ocean

Distribution map of Racovitzanus levis for the Zone China Seas, Vietnam

Localisations

Geographical glossary

NE Atlant. , Canary Is., Brazil (off Rio de Janeiro, The Campos Basin), off Amazon, Caribbean Sea, G. of Mexico, off Bermuda: Station ‘’ S’’ (32°10’N, 64°30’W), Sargasso Sea, off E Cape Cod, S Indian, China Seas (East China Sea, South China Sea), Japan (Sagami Bay), Oyashio region, Pacif. (W equatorial), Pacific (central gyres: N & S)

Quotations

N: 18

Dimensions (mm)

References of the authors concerning dimensions

(108) F: 2-1,95; M: 1,75; (199) F: 1,9; M: 1,67; (1000) F: 1,9 ± 0,1; {F: 1,80-2,00; M: 1,67-1,75}

Remarks

mesopelagic. Sargasso Sea: 0-1000 m (Deevey & Brooks, 1977, station "S"); In vertical tow 4000-3000 m (Harding , 1974). At 98-240 m in Station S1 (SE Hokkaido) in the Oyashio region.
Distributional range (m) from Roe (1972) Day: 450, Night: 360; from Grice & Hulsemann (1965): 450-1000 (in Kuriyama & Nishida, 2006).
For Grice & Hulsemann (1965, p.239) the female specimens agree with Tanaka's (1961) description, but the males differ in details of the terminal segment of exopod of right P5.

Last update : 19/01/2021

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