Calanoida ( Order )
    Pseudocyclopoidea ( Superfamily )
Pseudocyclopidae Giesbrecht, 1893 ( Pseudocyclopoidea )
Syn.: Ridgewayiidae M.S. Wilson, 1958.
Boholinidae Fosshagen & Iliffe, 1989.
Ref.: Giesbrecht, 1893 a (p.72); Giesbrecht & Schmeil, 1898 (p.125); Sars, 1902 (1903) (p.129); van Breemen, 1908 a (p.143); Gurney, 1931 a (p.85); Rose, 1933 a (p.247); Vervoort, 1964 a (p.8); Bradford, 1969 b (p.502, Table 3); Andronov, 1974 a (p.1005); Bowman & Abele, 1982 (p.10); Razouls, 1982 (p.385); 1993 (p.306); Othman & Greenwood, 1989 (p.63); Huys & Boxshall, 1991 (p.419, 466); Chihara & Murano, 1997 (p.891); Barthélémy, 1999 a (p.34); Bradford-Grieve, 1999 b (p.22); Ohtsuka & Huys, 2001 (p.461); Boxshall & Halsey, 2004 (p.13; 49; 166: Def.); Vives & Shmeleva, 2007 (p.976); Figueroa, 2011 (p.739); Blanco-Bercial & al., 2011 (p.103, Fig.3, molecular biology, phylogeny); Bradford-Grieve & al., 2014 (p.507, 526, Table 1, fig.11, cladistic analysis)
Bradford-Grieve J.M., (2002 onwards). Key to calanoid copepod families. Version 1 : 2 oct 2002.
Rem.: Type genus: Pseudocyclops Brady, 1872.
Hyperbenthic forms, littoral, offshore.
For Bradford-Grieve & al. (2014, p.507, 526) the genera included in this family are: Badijella, Boholina, Brattstromia, Exumella, Exumellina, Hondurella, Normancavia, Pinkertonius, Placocalanus, Pseudocyclops, Ridgeweyia, Robpalmeria, Stargatia, Stygoridgewayia. Total: 14 genera.

Diagnosis after Bradford-Grieve & al. (2014, p.526 ):
Female caudal rami of equal lengths (except Pinkertonius); male caudal rami usually symmetrical (except Stargatia); seta II spiniform.
Female A1 ancestral segment IV without aesthetasc. Tendency for aesthetascs to be absent from additional segments.
Md endopod well-developed, 2-segmented, ranging from greater than half length of exopod to extending well beyond exopod (except Exumella), segment 1 usually with 4 setae (except Robpalmeria, Normancavia, Exumella, Stargatia), segment 2 usually with between 8 and 11 setae (except Normancavia, Exumella, Exumellina, with have 6, 6, and 7 setae, respectively).
Mx1 coxal epipodite always with 9 setae.
Mx2 basis usually less than twice estimated length of coxa (except Exumella), basal endite usually elongate (except Placocalanus), and endopod setae normal (except Boholina which has spine-like setae).
Mxp endopod segments 2-6 usually longer than length of coxa (not including praecoxa) (except Placocalanus, Pseudocyclops) and endopod setae normal.
P1-P5 with both rami 3-segmented.
P1 basis posterior surface with tendency to have posterior surface process; exopod segment 2 with tendency to have outer distal corner produced into spinous lobe inner to articulated spine; exopod segment 3 with variable number of inner setae.
Female P5 has tendency towards specialization of joint between exopod seglments 2 and 3 composed of lengthening of outer distal part of segment 2, forming an oblique distal margin, and narrowing of proximal articulating region of segment 3; endopod reduced to 2 sehments in Boholina and reduced or absent in Ridgewayia.
Male P5 with inner process present on exopod segment 2; tendency towards reduction in arthropodial membrane formation in endopods and increasing complexity in form of exopods.
Family Pseudocyclopidae - Plate 1Issued from : J.M. Bradford-Grieve, G.A. Boxshall & L. Blanco-Bercial in Zool. J. Linn. Soc., 2014, 171. [p.525, Fig.11].
Strict consensus of one tree after one round of successive weighting. Clade numbers above the line. The out-group is Disseta palumbii Giesbrecht, 1889.

Family Pseudocyclopidae - Plate 2Issued from : J.M. Bradford-Grieve, G.A. Boxshall & L. Blanco-Bercial in Zool. J. Linn. Soc., 2014, 171. [p.528, Table 6].
Spine and seta formulae of swimming legs in Pseudocyclopidae.
Roman numerals = robust setae; Arabic numerals = setae. Outer border setation listed in first in each segmental group, and separated by ;

Family Pseudocyclopidae - Plate 3Issued from : G.A. Boxshall & S.H. Halsey in An Introduction to Copepod Diversity. The Ray Society, 2004, No 166, Part. I. [p.166].
Armature formula of swimming legs P1 to P4. P5 female.

Nota: Female P5 sometimes with endopodal segments fused and with setation elements reduced.
Male P5 asymmetrical with modified rami; intercoxal sclerite distinct or fused to protopods; coxa and basis separate or fused; right leg with 1 or 2-segmented exopod, bearing 2 strong, curved apical claws plus 2 or 3 other armature elements; endopod unsegmented, may be lobate or hook-like, typically unarmed. Left leg exopod 1 or 2-segmented, often with membranous process on distal segment; endopod 1-segmented, armed with up to 5 setae. Left basis with armature element arising on surface between origin of rami.- Eggs probably released into water.
(1) Pinkertonius Bradford-Grieve, Boxshall & Blanco-Bercial, 2014
Ref.: Bradford-Grieve & al., 2014 (p.517, GenBank, cladistic analyses)
Rem.: Type: Pinkertonius ambiguus Bradford-Grieve, Boxshall & Blanco-Bercial,2014. Total: 1 sp.
For Bradford-Grieve & al; (2014, p.528) the most distinctive shared characteristics that link this genus to the family Pseudocyclopidae are:
1- Absence of an aesthetasc on ancestral antennular segment IV;
2- Presence of a well-developed, elongate 2-segmented mandibular endopod with 10 terminal setae;
3- Presence of 9 setae on the coxal epipodite of Mx1;
4- Presence of a posterior surface process on the basis of P1;
5- Exopod segment 2 of female P5 distally extended, and articulation between segments 2 and 3 at an oblique angle to the main axis of the limb;
6- Right exopod segment 2 of male P5 with a triangular inner process and left exopod segment 2 with a scapel-like inner projection that is directed distally.
(2) Pseudocyclops Brady, 1872
Ref.: Brady & Robertson, 1873 (p.128); Brady, 1878 (p.81); Giesbrecht & Schmeil, 1898 (p.125); Sars, 1902 (1903) (p.130); van Breemen, 1908 a (p.143); Gurney, 1931 a (p.85); Sewell, 1932 (p.330); Rose, 1933 a (p.247); Nicholls, 1944 (p.10, spp. Key); Bowman & Gonzalez, 1961 (p.38, spp. Key); Vervoort, 1964 a (p.9, spp. Key, p.11); Tanaka, 1964 c (p.242); Fosshagen, 1968 (p.39); Dawson, 1977 (p.247); Razouls, 1982 (p.385); 1991 (p.169); Othman & Greenwood, 1989 (p.74); Barr & Ohtsuka, 1989 (p.331, 338); Huys & Boxshall, 1991 (p.466); Chihara & Murano, 1997 (p.891); Bradford-Grieve, 1999 b (p.23, Def.); 2004 (p.287); Boxshall & Halsey, 2004 (p.166; 158: species list); Vives & Shmeleva, 2007 (p.977, spp. Key); Bradford-Grieve & al., 2014 (p.522, Table 1, fig.9, 10, 11, cladistic analysis)
Rem.: Hyperbenthic forms generally on a littoral substrate. Type: Pseudocyclops crassiremis Brady,1871. Total: 39 spp. + 1 indet.

Diagnosis from Bradford-Grieve (199 b, p.23):
- Body short and compact, with anterior part considerably swollen.
- Head strongly vaulted, projecting ventrally an a sharply pointed rostrum, which is moveably connected to the head in male.
- Head and pediger segment 1 separate, pediger segments 4 and 5 fused or separate.
- Urosome 4-segmented in female; 5-segmented in male with a small anal segment.
- Caudal rami short with outermost seta spiniform.
- Eye distinctly developed.
- A1 longer than head, 15-48-segmented; right A1 male distinctly geniculate with the terminal part 4-segmented.
- A2 somewhat cyclopoid in shape; endopod 3-segmented and its distal part is aticulated to proximal segment at nearly a right angle; exopod about as long as endopod and 3-6-segmented.
-Md with distinctly biramous palp.
- Mx1 with the endopod considerably produced.
- Mx2 compact, with all finger-like lobes distinct.
- Mxp hardly longer than Mx2, with reduced setation.
P1-P4 powerfully built with strong outer edge spines on exopods.
P5 female with setae reduced in size, endopod short, 2-3-segmented.
- Male P5 somewhat asymmetrical, right leg larger and hooked at tip, endopod lamellar.

For Zagami & al. (2008, p.611) the five Pseudocyclops species occurring in Lake Faro (Sicily): P. umbraticus, P. xiphophorus, P. costanzoi, P. giussanii and Pseudocyclops sp. are all characterised (according to Ohtsuka & al. 1999) by the following synapomorphies and advanced features by a 2-segmented endopod of the female P5; the distal endopod segment of the female P5 with 1 medial and/or 2 terminal setae, and acute processes terminally; and the number of A1 segments of both sexes being 16 or 17.
The mirus-group shares synapomorphies as follows: 1- absence of exopodal setae along the inner margin of female P5; 2- unarmed proximal endopod segment of female P5, with 2 acute pointed processes; the distal endopod segment of the female P5 with 1 medial and 2 distal setae, and 3 or 4 processes terminally.
Nota: Synapomorphiy: common possession of a derived (apomorphic) homologous character, whereas the symplesiomorphy is the common possession of an ancestral (plesiomorphic) character.
Remarks on dimensions and sex ratio:
The mean female size is 0.685 mm (n= 63; SD = 0.1622) and the mean male size is 0.650 mm (n = 53 ; SD = 0.1524). The size ratio (Male : Female) is 0.948. The sex ratio Female : Male (37 : 33) = 1.12.
Suezia Gurney, 1927
Ref.: Gurney, 1927 d (p.457)
Rem.: type: Suezia canalis. Cf. Ridgewayia

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Razouls C., Desreumaux N., Kouwenberg J. and de Bovée F., 2005-2024. - Biodiversity of Marine Planktonic Copepods (morphology, geographical distribution and biological data). Sorbonne University, CNRS. Available at [Accessed July 25, 2024]

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