Leptaxinus minutus Verrill & Bush, 1898

Rodrigues, Clara F., Oliver, Graham & Cunha, Marina R., 2008, Thyasiroidea (Mollusca: Bivalvia) from the mud volcanoes of the Gulf of Cadiz (NE Atlantic), Zootaxa 1752, pp. 41-56 : 50-52

publication ID	https://doi.org/10.5281/zenodo.274249
persistent identifier	https://treatment.plazi.org/id/F6431C34-F712-E57C-FF27-F96C63EA8DCF
treatment provided by	Plazi
scientific name	Leptaxinus minutus Verrill & Bush, 1898
status

Treatment

(Fig. 30)

Material examined. All from Gulf of Cadiz; two live-collected specimens, MSM01-03, stn 242 GKG 13, Mercator mud volcano, 35 º 17.870 'N, 06º 38.810 'W, 350 m, 6 May 2006 ( DBUA 00835.01); one live-collected specimen, TTR 16, stn AT 608 Gr, Darwin mud volcano, 35 º 23.531 N, 07º 11.475 W, 1115 m, 30 May 2006 ( DBUA 00836.01); two live-collected specimens, TTR 16, stn AT 604 Gr, Yuma mud volcano, 35 º 25.820 N, 07º 06.330W, 1030 m, 29 May 2006 ( DBUA 00836.02).

PLATE 4. Figures 24–25: Thyasira (Parathyasira) granulosa ( Monterosato, 1874) , Fig. 24 stn 321 GKG 22, Meknès mud volcano, 732 m ( DBUA 00828.03), Fig. 25 stn 242 GKG 13, Mercator mud volcano, 350 m ( DBUA 00828.02); Fig. 26 Thyasira obsoleta ( Verrill & Bush, 1898) stn 190 MUC 8, Captain Arutyunov mud volcano, 1322 m, ( DBUA 00831.02); Fig. 27 Thyasira tortuosa ( Jeffreys, 1881) AT 622 Gr, Porto mud volcano, 3902 m ( DBUA 00830.01); Fig. 28 Axinulus croulinensis ( Jeffreys, 1847) stn 242 GKG 13, Mercator mud volcano, 350 m ( DBUA 00832.02); Fig. 29 Mendicula ferruginosa ( Forbes, 1844) stn AT 575 B, Mercator mud volcano, 355 m ( DBUA 000834.01); Fig. 30 Leptaxinus minutus Verrill & Bush, 1898 , stn AT 608 Gr, Darwin mud volcano, 1115 m ( DBUA 00836.01).

Remarks. Leptaxinus minutus is rather tumid with a distinctly angular posterior outline but lacking a posterior sinus. The hinge is well developed with weak lateral folds and a tubercular cardinal. It was described from the northwest Atlantic and has been recorded from Norway and Iceland (Ockelmann in Oliver & Killeen 2002). The Gulf of Cadiz specimens agree well with the shell figured by Oliver and Killeen ( 2002, Pl. 25 C, D) but comes from a much greater depth. Dufour ( 2005) did not examine this species but the Gulf of Cadiz specimens have a Type 2 gill with a single demibranch and according to similar forms described by this author, it will doubtfully be symbiotic.