Species Card of Copepod
Calanoida ( Order )
    Clausocalanoidea ( Superfamily )
        Scolecitrichidae ( Family )
            Lophothrix ( Genus )
Lophothrix humilifrons  Sars, 1905   (F,M)
Syn.: ? Lophothrix simplex Wolfenden, 1911 (p.268); Björnberg, 1973 (p. 387);
no Scaphocalanus pacificus Mori, 1932; 1937 (1964) (p.49);
no L. humilifrons (M) : C.B. Wilson, 1950 (p.250, figs.M)
Sars, 1905 b (p.22, Rem.F); 1925 (p.166, figs.F); Rose, 1933 a (p.145, figs.F); Jespersen, 1934 (p.87); Lysholm & al., 1945 (p.27); Sewell, 1947 (p.152, figs.F, Rem. F); Tanaka, 1961 a (p.152, figs.F); Vervoort, 1965 (p.60, Rem.); Owre & Foyo, 1967 (p.68, figs.F); Bradford, 1973 (p.144); Bradford & al., 1983 (p.88); Park, 1983 (p.177, 184, Redescr. F,M, figs.F,M); Bradford-Grieve & al., 1999 (p.881, 932, figs.F,M); Vives & Shmeleva, 2007 (p.747, figs.F, Rem.)
Species Lophothrix humilifrons - Plate 1 of morphological figuresissued from : T. Park in Antarct. Res. Ser. Washington, 1983, 38 (3). [p.185, Fig.11].
Female: a, forehead, (lateral); b, idem (ventral); c, last thoracic segments and urosome (lateral left side); d, rostrum (anterior); e, P1 (anterior); f, P2 (posterior); g, P3 (posterior); h, P4 (posterior); i, P5 (posterior).
Nota: Urosome about 22/100 length of prosome. A1 reaching about distal end of caudal rami.

Species Lophothrix humilifrons - Plate 2 of morphological figuresissued from : T. Park in Antarct. Res. Ser. Washington, 1983, 38 (3). [p.186, Fig.12].
Male: a, head (lateral); b, idem ((dorsal); c, last thoracic segments andurosome (dorsal); d, idem (lateral left side); e, rostrum (anterior); f, Mx1; g, Mx2; h, Mxp; i, P5 (right anterior); j, distal part of exopod of right P5 (anterior); k, idem (posterior).
Nota: 4th and 5th metasomal segments separate. Urosome about 37/100 length of prosome. A1 extending beyond distal end of metasome by last 2 segments.

Species Lophothrix humilifrons - Plate 3 of morphological figuresIssued from : G.O. Sars in Résult. Camp. Scient. Prince Albert I, 69, pls.1-127 (1924). [Pl.XLVI, figs.5-22].
Female: 15, habitus (dorsal); 16, idem (lateral left side); 17, forehead (lateral); 18, rostrum; 19, P1; 20, P2; 21, P3; 22, P5.

Species Lophothrix humilifrons - Plate 4 of morphological figuresissued from : R.B.S. Sewell in The John Murray Expedition, 1933-34, Scientific Reports, VIII (1), 1947. [p.153, Fig.39, A].
Female (from G. of Oman): A, genital segment and 2nd urosomal segment (ventral).
Nota: The proportional lengths of the cephalothorax and abdomen as 77 to 22. The proportional lengths of the various segments of the body (cephalon to caudal rami) as 350:186:106:80:35:20:95:44:34:24:26 = 1000. Head and 1st pediger segment almost completely fused, but a faint line of fusion can be traced across the dorsal region, similarly 4th and 5th almost completely fused. Caudal rami as broad as long and hairy on their inner aspects. A1 24-segmented (segments 8-9 fused) reaches back to the anal segment. The genital aperture presents certain differences, as will be seen from a comparison with L. frontalis.

Species Lophothrix humilifrons - Plate 5 of morphological figuresissue from : O. Tanaka in Publ. Seto Mar. Biol. Lab., 1961, IX (1). [p153, Fig.111].
Female (from Suruga Bay): a, habitus (dorsal); b, forehead (lateral); c, last thoracic segment and urosome (lateral, left side); d, P1; e, P2; f, P5.
- Cephalothorax about 4.16-4.26 times the abdomen length (5.2 : 1.25 or 81 to 19).
- Head and 1st pedigerous segment fused, 4th and 5th pediger segments fused.
- Head without crest.
- Forehead obtusely rounded in lateral aspect.
- Posterolateral corners of the last thoracic segment narrowly rounded.
- Rostrum strong, short and bifurcate.
- Urosome 4-segmented; abdominal segments and caudal rami in yje proportional lengths 39 : 18 : 14 : 18 : 11 = 100.
- Genital segment about as long as wide.
- Abdominal segments 1 to 3 fringed with fine teeth on distal margin.
- Caudal rami longer than wide (20: 18).
- A1 24-segmented, exceeds the distal end of the caudal rami by terminal 1 segment.
- A2 exopod about as long as endopod; distal segment of exopod short.
- Mouthparts and swimming legs as those of Lophothrix frontalis Giesbrecht.
- P5 3-segmented, resembles that of L. frontalis; 1st and 2nd segments furnished coarsely with small spines on the anterior surface.

Species Lophothrix humilifrons - Plate 6 of morphological figuresissued from : H.B. Owre & M. Foyo in Fauna Caribaea, 1, Crustacea, 1: Copepoda. Copepods of the Florida Current. [p.67, Figs.429, 434].
Female (from 14°55'N, 64°50'W): 429, habitus (lateral); 434, P5.

Nota: Forehead without a crest; P5 with the internal spine much longer than the external.

Species Lophothrix humilifrons - Plate 7 of morphological figuresissued from : H.B. Owre & M. Foyo in Fauna Caribaea, 1, Crustacea, 1: Copepoda. Copepods of the Florida Current. [p.25, Fig.116].
Female: 116, rostrum.

Species Lophothrix humilifrons - Plate 8 of morphological figuresissued from : O. Tzanaka in Publ. Seto Mar. Biol. Lab., 1961, IX (1). [p.153].
Female: Proportional lengths of the segments of A1.

Compl. Ref.:
Wilson, 1942 a (p.191); Sewell, 1948 (p.331, 521, 533, 548, 566, 568); Fagetti, 1962 (part., p.24); Grice & Hulsemann, 1967 (p.16); 1968 (tab.2); Björnberg, 1973 (p.333, 387); Harding, 1974 (p.141, tab.2, gut contents); Frontier, 1977 a (p.15); Deevey & Brooks, 1977 (p.256, tab.2, Station "S"); Vives, 1982 (p.292); Lozano Soldevilla & al., 1988 (p.58); Park & Ferrari, 2009 (p.143, Table 4, Appendix 1, biogeography)
NZ: 11

Distribution map of Lophothrix humilifrons by geographical zones
Antarct., Sub-antarct. (in Park, 1983), G. of Guinea, off W Cape Verde Is., off Morocco-Mauritania, Canary Is., off Madeira, Portugal, off Cape Finisterre, Bay of Biscay, Azores, Caribbean, off Bermuda: Station ‘’ S’’ (32°10’N, 64°30’W), Caribbean Sea, off E & SE Cape Cod, S Davis Strait, G. of Oman, Madagascar (Nosy Bé), Indian, Japan (in Tanaka, 1961), SE Easter Is.(in Wilson, 1942 a, p. 82), off Juan Fernandez Is., Peru
N: 23
(1) F: 6,3; (6) F: 7,33-5,5; (11) F: 5,913; (108) F: 6,45; {F: 5,50-7,33}
Rem.: Bathypelagic. Sargasso Sea: 1500-2000 m (Deevey & Brooks, 1977, station "S"); 2000-1000 m (Harding, 1974).
Probable in this Genus.
Vervoort (1965, p.60) does not include Wilson's L. humilifrons into the synonymy of this species, because Wilson's specimens are exclusively male from the Albatros Expedition (1950), but the Vervoort's impression is that probably the species should be Scottocalanus thomasi A. Scott, of which species females are recorded from the same station (off Bataan, Philippines).
For Park (1983, p.187) both the female and male are similar to L. frontalis may be easily distinguished.
Last update : 24/03/2017
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