Rhincalanidae Family - Marine Planktonic Copepods

Calanoida ( Order )	details
Eucalanoidea ( Superfamily )	details

Abbreviations or symbols

Rhincalanidae Geletin, 1976 ( Eucalanoidea )

Syn.:

Rhincalaninae : Geletin, 1976 (p.92);
Eucalanidae : Brodsky, 1950 (1967, p.99); Bradford-Grieve, 1994 (p.74: Rem..

Ref.:

Boxshall & Halsey (2004, p.116) consider this sub-family as a true family. Vives & Shmeleva, 2007 (p.885); Blanco-Bercial & al., 2011 (p.103, Table 1, Fig.2, 3, 4, Biol. mol, phylogeny); Laakmann & al., 2019 (p.330, fig. 2, 3, phylogenetic relationships)

Rem.:

1 G: Rhincalanus.

For Brodsky (1950 [1967]) the differences between the genera Eucalanidae and Rhincalanidae are: absence of P5 from female, the absence of spines on thorax and abdomen, and pair of legs P5 uniramous in male for the first, and P5 present in female, thorax and abdomen spinose in female, and one of the legs P5 of male biramous for the latter.

Issued from : G.A. Boxshall & S.H. Halsey in An Introduction to Copepod Diversity. The Ray Society, 2004, No 166, Part. I. [p.175].
Armature formula of swimming legs P1 to P4.
Nota: All outer margin spines on exopodal segments of P2 to P4 fused to segments.
- Female P5 comprising bilobed transverse plate representing intercoxal sclerite fused to coxae, basis, plus 1-segmented exopod. Basis unarmed or bearing inner seta representing endopod. Exopodal segment with distal spine or spinous process and 1 or 2 setae.
- Male P5 asymmetrical; right leg uniramous, 3-segmented; 1st and 2nd segments unarmed, 3rd segment bearing curved apical spine and, in some species, subapical spinous process. Left leg biramous, comprising unarmed, separate coxa and basis, 2-segmented endopod and 1-segmented exopod armed with distal claw plus up to 4 inner margin setae and outer spinous process.
- Eggs released into water.

(1) Rhincalanus Dana, 1852

Species, varieties and details

Syn.:

Calanus (part.) : Dana,1846

Ref.:

Giesbrecht, 1892 (p.47, 152); Giesbrecht & Schmeil, 1898 (p.22); Sars, 1901 a (1903) (p.14); Esterly, 1905 (p.135); van Breemen, 1908 a (p.17); A. Scott, 1909 (p.23); Wolfenden, 1911 (p.193); Schmaus & Lehnhofer, 1927 (p.358); Sewell, 1929 (p.58); Wilson, 1932 a (p.34); Rose, 1933 a (p.70); Mori, 1937 (1964) (p.26); Vervoort, 1946 (p.116); Brodsky, 1950 (1967) (p.106); Farran & Vervoort, 1951 b (n°34, p.3); Tanaka,1956 (p.270); Bowman,1971 (p.18); Sheldon & al., 1972 (p.327, fig. 13: size particle vs production's rate); Andronov, 1973 b (p.1720, Rem.); Geletin, 1976 (p.90, Rem.); Björnberg & al., 1981 (p.619); Razouls, 1982 (p.98); Gardner & Szabo, 1982 (p.159); Brodsky & al., 1983 (p.200); Zheng Zhong & al., 1984 (1989) (p.229); Hiromi, 1987 (p.150); Mauchline, 1988 (p.723); Huys & Boxshall, 1991 (p.51, 68); Razouls, 1993 (p.309); Bradford-Grieve, 1994 (p.84, Déf.); Chihara & Murano, 1997 (p.787); Mauchline, 1998 (p.77); Bradford-Grieve & al., 1999 (p.912, clé spp.); Boxshall & Halsey, 2004 (p.176: spp. Key); Mulyadi, 2004 (p.120, Def.); Vives & Shmeleva, 2007 (p.885, spp. Key)

Rem.:

type: Rhincalanus cornutus Dana,1849. Total: 4 spp.

Diagnosis from Bradford-Grieve (1994, p.74) :
- As in the family definition.
- Urosome female 3-segmented, and the posterior borders of some or all pedigers 2-4 and urosomal segment 1 with dorsal spines.
- A2 endopod squat ; exopod segments 1 and 2 separate.
- Md palp basis and exopod squat ; endopod normal, inserted terminally on basis which also bears 4 setae.
- Mx1 with 2 inner lobes bearing setae, inner lobe 2 present but without setae.
- P1 with a 2-segmented endopod and exopod.
- P5 female present, uniramous on both sides.
- P5 male uniramous on the right and biramous on the left.

Key to species (based on females) after Boxshall & Halsey (2004, p.176) :
1 - Female P5 lacking setal element on middle segment; distal segment drawn out into tapering point and carrying large, serrated inner spine ........ R. rostrifrons.
1' - Female P5 with 1 or 2 inner setae on middle segment; distal segment with 2 inner plumose setae and terminal spine (which may be short and naked or long and plumose) ...... 2.
2 - Female P5 with naked outer terminal spine, shorter than its segment ........ R. cornutus.
2' - Female P5 with terminal spine plumose (at least on one side), much longer than segment ..... 3.
3 - 3rd and 4th pedigerous somites each with paired spinous processes dorsally on posterior margin ...... R. gigas.

Remarks on dimensions and sex ratio:

The mean female size is 4.913 mm (n = 8; SD = 2.6563), and the mean male size is 3.647 mm (n = 7; SD = 1.6229). The coefficients of variance indicate a strong heterogeneity of the sizes (for females between 2.41 mm to 10.0 mm. and for males: 2.40 mm to 6.90 mm). , however the size ratio male: female for all species is 0.836 (n = 4; SD = 0.0364) or respectively for each species: 0.872; 0.802; 0.807 and 0.862.
The sex ratio (female: male) is 1.