Kyphocalanus
- Dataset
- A new family and genus of calanoid copepods (Crustacea) from the abyss of the Atlantic Ocean
- Rank
- GENUS
Classification
- kingdom
- Animalia
- phylum
- Arthropoda
- class
- Maxillopoda
- order
- Calanoida
- family
- Kyphocalanidae
- genus
- Kyphocalanus
description
Description. Female. Prosome 5.3 times as long as urosome. Rostrum with two strong rami (Fig. 9 C). Cephalosome and somite 1 and somites 4 and 5 of prosome separate; posterior corners as triangular lobes (Fig. 9 A – B). Caudal rami with 4 terminal setae, 1 ventral seta, dorsal seta not located (Fig. 9 B). Antennule entirely lost. Antenna, attributes of type species. Mandible (Fig. 10 A), gnathobase with 4 acutely pointed and 4 very small teeth plus dorsal seta; basis with 2 setae, proximal one larger and with proximal part haft-like; exopod 4 (?) - segmented with 5 setae; endopod segment 1 without setae, segment 2 with 9 setae. Maxillule, shape similar and setation identical to that of type species. Maxilla (Fig. 10 C-D), proximal praecoxal endite with 2 setae; distal praecoxal endite with 2 setae; proximal coxal endite with 2 setae; distal coxal endite with 2 setae; proximal basal endite with 1 spine; distal basal endite plus endopod with 8 long and thick worm-like sensory setae. Maxilliped (Fig. 9 D), syncoxa with 1 worm-like, comparably thin and short sensory seta on proximal praecoxal lobe, 2 long and thick worm-like setae on middle lobe; distal praecoxal lobe without setae; coxal lobe with 1 seta. Basis with 3 setae. Endopod 6 - segmented with 2, 4, 2, 2, 2 + 1, and 4 setae. Swimming legs. P 1 (Fig. 9 E), basis with medial distal seta only slightly curved, with setules; endopod 1 - segmented without lateral lobe; exopod segments 1, 2 and 3 with lateral spines, proximal spine is the shortest; spine of exopod segment 1 exceeding base of following spine, spine of exopod segment 2 not reaching base of following spine. Intact segments of P 2 – P 4 as in type species, except for P 4 surface not spinulated. P 5 (Fig. 9 F) 3 - segmented, similar to type species, but exopod surface spinules absent.
discussion
Remarks. Kyphocalanus sp. 2 differs from K. atlanticus in the shape of rostrum, its rami being more closely spaced (Figs. 1 C, 9 C) and in the presence of 3 setae on inner lobe of antenna endopod segment 2 (vs 4 setae in K. atlanticus). From all congeners it is distinct in that spinules are absent on the posterior surface of P 5; from Kyphocalanus sp. 1 it can be distinguished by the ratio of the lengths of P 5 exopodal spines. It shares with the type species the following characteristics that differentiate both from Kyphocalanus sp. 1: i) its larger size (2.10 – 2.24 mm vs 1.82 mm in Kyphocalanus sp. 1); ii) a longer endopod of antenna (ratio of exopod and endopod lengths as 1.8 vs 2.3 in Kyphocalanus sp. 1); iii) presence of 2 setae on maxilla proximal coxal endite (vs 1 seta); iv) and P 1 lateral spine of exopod segment 1 shorter than spines of exopod segments 2 and 3 (this spine is the longest in Kyphocalanus sp. 1).
materials_examined
Material examined. Dissected adult female, body length 2.10 mm. Collected in 1998 above the sea bed at abyssal depths (4800 m) on Porcupine Abyssal plain (48 º 58 ’ N 16 º 30 ’ W). Specimen is deposited at the Zoological Museum Hamburg (ZMH), University of Hamburg.
Name
- Homonyms
- Kyphocalanus
- Kyphocalanus
- Kyphocalanus
- Kyphocalanus