Giesbrecht, 1895
Short Description:
Chirundina streetsii is an aetideid calanoid copepod known after both sexes (female 4.15-5.55 mm and male 3.80-5.20 mm) from the Atlantic, Pacific and Indian oceans, mainly in epi- and mesopelagic waters.
Taxonomic Description:
Female. Total length 4.15-5.55 mm. Cephalothorax about 3-4 times longer than abdomen. High crest present. Posterior Th5 corners slightly prolonged, often ending with small knob or tooth, their shape may vary (With, 1915, text-fig. 38 b, c, d, e, j) which is especially visible when looking laterally. A1 24-segmented, longer than cephalothorax, often reaching the distal end of caudal rami. Re A2 1.5 times longer than Ri A2. P1 with indistinct separation between Re1 and Re2, each segment is supplied with external spine, Ri one-segmented. P2 with one-segmented Ri with weak traces of separation visible (into 2 segments), and 3-segment Re. P3-P4 rami 3-segmented.
Male. (Description after Tanaka (1957b); Tanaka and Omori (1970b) and With (1915) with modifications). Total length 3.80-5.20 mm. Cephalothorax 2.7-3.8 times longer than abdomen. Cephalon with crest, lower than in female. Posterior Th5 corners rounded. Abd 2-4 supplied with row of spinules along posterior border. A1 reaching the midlength of Abd, left 21, right 20-segmented. Mx1, Mx2 and Mxp rudimentary. P1-P4 with the same segmentation as in female. External spine on Re1 P1 shorter than in female. P5 close in structure to that in Undeuchaeta plumosa , Ri one-segmented, right slightly shorter, left slightly longer than Re1 of the corresponding leg. Re1 P5 right with 2 big and 1 small teeth proximally on the external edge; Re2 of that leg with groove and terminal spine, the latter is two thirds of segment in length. Re of left leg 3-segmented, Re2 comparatively short with short spine with obtuse tooth and rounded projection.
Vertical distribution:
The species was found in the hauls from epi- and mesopelagic (Grice, 1962; Park, 1970; Tanaka and Omori, 1970b; Roe, 1984b), single findings known from bathypelagic (Grice and Hulsemann, 1967). Recorded also in total hauls from 8000 m. Roe noted that species shows vertical migration and serves as food to few decapod species (Roe, 1984).
Geographical distribution:
Widespread in the North Atlantic, the most northern finding: 63,5°N (With, 1915), in equatorial zone: the Gulf of Guinea (Vervoort, 1963), to the South from equator in Atlantic found in the region of 35°S (Wolfenden, 1911), recorded in the Indian Ocean: from the Arabian Sea (Sewell, 1947) to the region of 31°S in the western and to 43°S in the eastern (Markhaseva, 1996) part of Ocean; in the Pacific Ocean species was not recorded to the North from 35°N (Tanaka and Omori, 1970b; Giesbrecht, 1895); found in equatorial zone (Grice, 1962); in the western part of Ocean from Japanese waters to New Zealand (Bradford and Jillett, 1980), in eastern part from 35°N to 32-33°S (Bjornberg, 1973; Markhaseva, 1996), in the antarctic sector of the Pacific Ocean in the region of 54°S (Park, 1978).
Type locality: the region of California: 35°N 125°E (Giesbrecht, 1895).
Material examined:
41 females from samples: 49, 201, 202, 390-392, 395, 400, 401, 444. See examined samples module.