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Family
Mecynoceridae Andronov, 1973 ( Calanoidea )
Syn.:
Mecynoceridae : Andronov, 1970 (p.985, Rem.); 1973 b (p.1721); 1974 a (p.1005); Razouls, 1982 (p.101); Bowman & Abele, 1982 (p.10); Brodsky & al., 1983 (p.142, 147, 216); Mauchline, 1988 (p.722: pores cuticulaires); Hiromi, 1987 (p.147, Rem.); Nishida, 1989 (p.174); Bradford-Grieve, 1994 (p.71, Rem.); Chihara & Murano, 1997 (p.833); Barthélémy, 1999 a (p.30); Bradford-Grieve & al., 1999 (p.878, 902, 905, 911); Ohtsuka & Huys, 2001 (p.461); Boxshall & Halsey, 2004 (p.14; 49; 136: Def.); Vives & Shmeleva, 2007 (p.907); Cornils & Blanco-Bercial, 2013, p.861, figs.1, 3, 5, phylogeny, molecular analysis); Ohtsuka & Nishida, 2017 (p.568, Rem. concerning the 3 families Calocalanidae, Mecynoceridae and Paracalanidae).
Bradford-Grieve J.M., (2002 onwards). Key to calanoid copepod families. Version 1 : 2 oct 2002. http://www.crustacea.net/crustace/calanoida/index.htm
Rem.: 1 G.: Mecynocera.
Ref.:
Bradford-Grieve, 2008 (p.59, Rem.).
Rem.:
1 G.: Mecynocera.
Previously placed in the subfamily of the Eucalaninae by Giesbrecht, 1892 (p.45, 47), then in the Eucalanidae (Sars, 1902, p.14), next in the Calocalanidae Bernard, 1958 a (p.199). Placed in the Paracalanidae family by Bradford-Grieve 2008 (p.59) and Cornils & Blanco-Bercial, 2013 (p.861, 870).
Taxonomic notes after Boxshall & Halsey (2004, p.136) (summary) :
- Body slender.
- Cephalosome and 1st pedigerous somite separate or no.
- Male with dorsal cephalic hump on cephalothorax.
- Posterolateral angles of prosome rounded.
- Urosome female 3-segmented.
- Genital apparatus female comprising common genital aperture located medially on ventral surface of genital double-somite ; copulatory pore contained within median genital aperture.
- Urosome male apparently 5-segmented in male ; comprising genital somite and 4 free abdominal somites ; single genital aperture located ventrolaterally on right side at posterior rim of genital somite.
- Caudal rami short, separate at base, with up to 6 setae.
- Rostrum divided into paired rostral filaments.
- Nauplius eye present.
- A1 much longer than body, 23-segmented in female with considérable fusion of proximal segments ; segmental homologies : segment ½ compound (I-IV), segment 3 (V) to 7 (IX) separate, segments 8 (X) and 9 (XI) fused, segments 10 (XII) to 21 (XXVI) separate, apical (23rd) seggment double (XXVII-XXVIII) ; proximal segments with non-functional sutures making plane of fusion between segments 1 (I-IV) and 7 (XI). Aesthetascs present on segments III, V, VII, XI, XXI and XXVI-XXVIII. Many setae unusually long. Mid-length segments especially elongate, ornamented with rows of spinules along posterior margins.
- A1 non-geniculate in males, shorter than in female ; 20-segmented (according to Andronov, 1973) with additional segmental fusions, 1 and 2 (I-IV) and 3 to 6 (V-VIII), and thickenings proximally.
- A2 biramous, with separate coxa and basis ; coxa with 1 seta ; basis with 2 setae ; endopod 2-segmented ; compound distal segment bilobed ; setation formula 2, 9+7 ; exopod 8-segmented, shorter than endopod, terminal segment short ; segmental fusions : I-II, III-IV, V, VI, VII, VIII, IX, X ; setation formula : 2, 2, 1, 1, 1, 1, 1, 3.
- Md with well developed coxal gnathobase ; palp consisting of basis, armed with 4 setae, 2-segmented endopod and 5-segmented exopod ; endopodal segments 1 and 2 with 4 and 10 setae ; exopodal setation formula 1, 1, 1, 1, 2.
- Mx1 with well developed praecoxal arthrite bearing about 12 elements, including 4 setae on posterior surface ; coxa with endite bearing 3 setae and 9 setae on epipodite ; basis without outer seta, with proximal endite bearing 2/3 setae and distal group of 4 setae representing distal endite ; endopod distinctly 3-segmented, setation formula 4, 4, 6/7 ; exopod 1-segmented, armed with 11 setae.
- Mx2 7-segmented ; praecoxa and coxa separate, setation formula of endites 4/5, 3, 3, 3 ; allobasdis with ¾ setae on basal endite and 2 on first endopodal endite, free endopod indistinctly segmented, with total og 6 setae.
- Mxp 7-segmented ; syncoxa with endite setation formula 1, 2, 3, 4 ; basis armed with 3 setae, plus 2 setae on incorporated first endopodal segment, ornamented with medial spinule row proximal to basal setae, free endopod 5-segmented, segmental setation formula 4, 4, 3, 2+1, 4.
- Swimming legs 1 (P1) to 4 (P4) biramous with 3-segmented rami, except for 1-segmented or indistinctly 2-segmented endopod of leg . P1 with group tiny spinules at outer distal angle. Second endopodal segment of legs 2 to 4 ornamented with conspicuous spinule row, smaller spinules present on exopodal and distal endopodal segments.
Previously placed in the subfamily of the Eucalaninae by Giesbrecht, 1892 (p.45, 47), then in the Eucalanidae (Sars, 1902, p.14), next in the Calocalanidae Bernard, 1958 a (p.199). Placed in the Paracalanidae family by Bradford-Grieve 2008 (p.59) and Cornils & Blanco-Bercial, 2013 (p.861, 870).
Taxonomic notes after Boxshall & Halsey (2004, p.136) (summary) :
- Body slender.
- Cephalosome and 1st pedigerous somite separate or no.
- Male with dorsal cephalic hump on cephalothorax.
- Posterolateral angles of prosome rounded.
- Urosome female 3-segmented.
- Genital apparatus female comprising common genital aperture located medially on ventral surface of genital double-somite ; copulatory pore contained within median genital aperture.
- Urosome male apparently 5-segmented in male ; comprising genital somite and 4 free abdominal somites ; single genital aperture located ventrolaterally on right side at posterior rim of genital somite.
- Caudal rami short, separate at base, with up to 6 setae.
- Rostrum divided into paired rostral filaments.
- Nauplius eye present.
- A1 much longer than body, 23-segmented in female with considérable fusion of proximal segments ; segmental homologies : segment ½ compound (I-IV), segment 3 (V) to 7 (IX) separate, segments 8 (X) and 9 (XI) fused, segments 10 (XII) to 21 (XXVI) separate, apical (23rd) seggment double (XXVII-XXVIII) ; proximal segments with non-functional sutures making plane of fusion between segments 1 (I-IV) and 7 (XI). Aesthetascs present on segments III, V, VII, XI, XXI and XXVI-XXVIII. Many setae unusually long. Mid-length segments especially elongate, ornamented with rows of spinules along posterior margins.
- A1 non-geniculate in males, shorter than in female ; 20-segmented (according to Andronov, 1973) with additional segmental fusions, 1 and 2 (I-IV) and 3 to 6 (V-VIII), and thickenings proximally.
- A2 biramous, with separate coxa and basis ; coxa with 1 seta ; basis with 2 setae ; endopod 2-segmented ; compound distal segment bilobed ; setation formula 2, 9+7 ; exopod 8-segmented, shorter than endopod, terminal segment short ; segmental fusions : I-II, III-IV, V, VI, VII, VIII, IX, X ; setation formula : 2, 2, 1, 1, 1, 1, 1, 3.
- Md with well developed coxal gnathobase ; palp consisting of basis, armed with 4 setae, 2-segmented endopod and 5-segmented exopod ; endopodal segments 1 and 2 with 4 and 10 setae ; exopodal setation formula 1, 1, 1, 1, 2.
- Mx1 with well developed praecoxal arthrite bearing about 12 elements, including 4 setae on posterior surface ; coxa with endite bearing 3 setae and 9 setae on epipodite ; basis without outer seta, with proximal endite bearing 2/3 setae and distal group of 4 setae representing distal endite ; endopod distinctly 3-segmented, setation formula 4, 4, 6/7 ; exopod 1-segmented, armed with 11 setae.
- Mx2 7-segmented ; praecoxa and coxa separate, setation formula of endites 4/5, 3, 3, 3 ; allobasdis with ¾ setae on basal endite and 2 on first endopodal endite, free endopod indistinctly segmented, with total og 6 setae.
- Mxp 7-segmented ; syncoxa with endite setation formula 1, 2, 3, 4 ; basis armed with 3 setae, plus 2 setae on incorporated first endopodal segment, ornamented with medial spinule row proximal to basal setae, free endopod 5-segmented, segmental setation formula 4, 4, 3, 2+1, 4.
- Swimming legs 1 (P1) to 4 (P4) biramous with 3-segmented rami, except for 1-segmented or indistinctly 2-segmented endopod of leg . P1 with group tiny spinules at outer distal angle. Second endopodal segment of legs 2 to 4 ornamented with conspicuous spinule row, smaller spinules present on exopodal and distal endopodal segments.
Figures
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Plate 1
Issued from : G.A. Boxshall & S.H. Halsey in An Introduction to Copepod Diversity. The Ray Society, 2004, No 166, Part. I. [p.136].
Armature formula of swimming legs P1 to P4.
Nota: Female P5 comprising 2-segmented protopod and 3-segmented exopod; 2nd exopodal segment armed with inner seta; distal exopodal segment bearing 1 to 6 setation elements around apex and inner margin (according to different descriptions).
-Male P5 asymmetrical, both uniramous and 5-segmented; coxa fused to intercoxal sclerite; basis free, unarmed; exopod 3-segmented, distal segment armed with 2 apical spines, 1 large and 1 small; legt leg longer than right.
- Eggs released into water.
Issued from : G.A. Boxshall & S.H. Halsey in An Introduction to Copepod Diversity. The Ray Society, 2004, No 166, Part. I. [p.136].
Armature formula of swimming legs P1 to P4.
Nota: Female P5 comprising 2-segmented protopod and 3-segmented exopod; 2nd exopodal segment armed with inner seta; distal exopodal segment bearing 1 to 6 setation elements around apex and inner margin (according to different descriptions).
-Male P5 asymmetrical, both uniramous and 5-segmented; coxa fused to intercoxal sclerite; basis free, unarmed; exopod 3-segmented, distal segment armed with 2 apical spines, 1 large and 1 small; legt leg longer than right.
- Eggs released into water.
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Plate 2
Issued from : G.A. Boxshall & S.H. Halsey in An Introduction to Copepod Diversity. The Ray Society, 2004, No 166, Part. I. [p.137, Fig.28].
Mecynoceridae. A, Mecynocera clausii habitus female; B, female P5; C, Mxp; D, habitus male; E, male P5. [Giesbrecht, 1893a (1892): A-C; Brodsky & al., 1983: D-E].
Issued from : G.A. Boxshall & S.H. Halsey in An Introduction to Copepod Diversity. The Ray Society, 2004, No 166, Part. I. [p.137, Fig.28].
Mecynoceridae. A, Mecynocera clausii habitus female; B, female P5; C, Mxp; D, habitus male; E, male P5. [Giesbrecht, 1893a (1892): A-C; Brodsky & al., 1983: D-E].