Metacrangon knoxi ( Yaldwyn, 1960 )

Komai, Tomoyuki & Ahyong, Shane T., 2010, The crangonid shrimp genus Metacrangon (Crustacea: Decapoda: Caridea) from New Zealand, with descriptions of four new species, Journal of Natural History 45 (1 - 4), pp. 77-111 : 102-103

Metacrangon knoxi ( Yaldwyn, 1960)

( Figure 16 )

Sclerocrangon n. sp. – Richardson and Yaldwyn 1958, p. 40, fig. 43.

Sclerocrangon knoxi – Yaldwyn 1960, p. 35, fig. 7 [type locality: Chatham Rise].

Metacrangon knoxi – Zarenkov 1965, p. 1764; Crosnier and Forest 1973, p. 238; Komai 1997, p. 670, figs 1E, 8.

Material examined

Paratypes. Chatham Rise, 44 ◦ 04 ′ S, 178 ◦ 04 ′ W, 468 m, Chatham Islands 1854 Expedition , stn 52, 10 February 1954, seven females (CL 6.8–10.8 mm), two males (CL 7.0, 8.3 mm), CM AQ1228 .

Non-types. Chatham Rise, 43 ◦ 32.99–33.60 ′ S, 179 ◦ 48.00–49.30 ′ E, 395–413 m, dredge, stn 868, 18 December 1976, one female (CL 9.5 mm), NIWA 58583 ; 43 ◦ 37.71–37.89 ′ S, 178 ◦ 36.64–36.67 ′ W, 420–426 m, beam trawl, TAN0705 / 185, 18 April 2007, one ovigerous female (CL 9.8 mm; egg diameter 1.85 mm), NIWA 42662 ; 43 ◦ 20.12 ′ S, 178 ◦ 58.88 ′ E , 418 m, stn V0372 , 13 September 1989, one female (CL 9.4 mm), NIWA 58584 ; 44 ◦ 07.87–08.11 ′ S, 174 ◦ 50.67–50.64 ′ E, 516–518 m, TAN0705 / 25, 4 May 2007, two ovigerous females (CL 10.0– 10.3 mm), NIWA 33007 ; 43 ◦ 58.8–59.04 ′ S, 179 ◦ 37.89– 37.45 ′ E, 531–532 m, TAN0705 / 84, 9 May 2007, two females (CL 9.9–10.0 mm), NIWA 33020 ; 44 ◦ 07.87–08.11 ′ S, 174 ◦ 50.67–50.64 ′ E, 516–518 m, TAN0705 / 25, 4 May 2007, one male (CL 5.8 mm), one ovigerous female (CL 10.3 mm), NIWA 33004 ; 43 ◦ 49.95–49.60 ′ S, 176 ◦ 42.82–42.33 ′ E, 477–479 m, TAN0705 / 34, 5 May 2007, one female (CL 7.4 mm), NIWA 33008 .

Size

Largest female CL 10. 3 mm, ovigerous females CL 9.8–10.3 m; male CL 5.8 mm.

Remarks

Komai (1997) gave a diagnosis of this species based on an examination of the paratypes, but the following diagnostic details could be added: rostral tip acutely pointed in dorsal view ( Figure 16A ), lateral margin nearly straight in lateral view ( Figure 16B ); eye about as long as wide, with rounded dorsal tubercle on eyestalk ( Figure 16A,B ); dorsolateral distal angle of antennal basicerite sharply pointed ( Figure 16A,B ).

The present specimens constitute additional records of Metacrangon knoxi for the Chatham Rise and slightly extend the known bathymetric range. Despite widespread sampling around New Zealand in the five decades since M. knoxi was first described, no specimens of the species have been found beyond the Chatham Rise, suggesting that the species might be locally endemic.

Distribution

Presently known only from the Chatham Rise; 395–532 m.

Figures

Figure 16. Metacrangon knoxi (Yaldwyn, 1960), paratype, female (CL 10.8 mm), CM AQ1228. (A) Anterior part of carapace (left side) and left cephalic appendages, dorsal view; (B) same, lateral view. Scale bar: 2 mm.