Fusinus chocolatus (Okutani, 1983)

Lyons, William G. & Snyder, Martin Avery, 2019, Fasciolariidae (Gastropoda: Neogastropoda) of French Guiana and nearby regions, with descriptions of two new species and comments on marine zoogeography of northeastern South America, Zootaxa 4585 (2), pp. 239-268 : 252-253

Fusinus chocolatus (Okutani, 1983)

( Figures 13–14 )

Barbarofusus chocolatus Okutani, 1983: 23 –25, fig. 10; Okutani, 1991: 165; Snyder, 2003: 65.

Fusinus chocolatus: Hadorn & Rogers, 2000: 14 , 15, 23, 30, 39, 52, pl. 4, figs. 42–45 (off St. Vincent, 245 m; Cabo Codera and Punta Piedras, northern Venezuela, 128 and 257 m; Tobago, 146 m; Suriname, 146 m; French Guiana, 130 m); Massemin et al., 2001: 19; Massemin et al., 2009: 154 (pars); Mallard & Robin, 2017: 27, fig. 2 (pars; Colombia to Maranhão, Brazil (map); 40–65 mm sl; depth 100–180 m; figured shell 39 mm sl from Paramaraibo, Suriname); non Fusinus chocolatus Mallard & Robin (2005: pl. 18, fig.) , nec Massemin et al. (2009: 154, 155, fig.), Guadeloupe, nec Mallard & Robin (2017: 27, fig.. 1, Guadeloupe and fig. 3, Los Monjes, Colombia), nec Lamy & Pointier (2017: 315, 317, fig. 7a, b), Guadeloupe.

Fusinus lightbourni: Daccarett & Bossio, 2011: 100 (Golfo de Morrosquillo, Colombia, 100 m); non F. lightbourni Snyder, 1984 , Bermuda.

Fusinus libtbourni (sic): Daccarett & Bossio, 2011: 259, fig. 496 (Colombian specimen figured); non F. lightbourni Snyder, 1984 .

Types. Holotype: 64.5 mm, off Suriname, 7°25’N, 54°15’W, 180 m, NSMT-Mo. 61203 (Okutani, 1983: 284, figs; Hadorn & Rogers 2000: 39, figs. 42, 43) . Paratype: NSMT-Mo. 61204, same locality as holotype ( Hadorn & Rogers 2000: 39, figs. 44, 45).

Material examined. French Guiana —1-dd, 29.5 mm (IM-2012-20354), GUYANE sta. CP 4358, 06°55’N, 53°05’W, 103 m, 30 Jul 2014; 1-dd, 25.3 mm, same station; 2-lv, 40.8 mm (IM-2013-56457) and 45.9 mm (IM- 2013-56458), GUYANE sta. CP 4377, 06°36’N, 52°29’W, 157– 162 m. Venezuela —1-dd, 72.5 mm, off Venezuela, deep water, 1985, ANSP 465699.

Remarks. The GUYANE collections contained four specimens from two stations, depths 103 and 162 m. This uncommon species attains a maximum size of 72.5 mm sl (ANSP 465699), so the specimens from French Guiana (25.3–45.9 mm sl) are rather small. Most known specimens were taken in exploratory fishing surveys by the R/V Oregon and in investigations of deep-water fauna by the University of Miami. The previous depth range is 128–257 m ( Hadorn & Rogers 2000), rounded up to 130 m by Massemin et al. (2009), but a record misidentified as F. lightbourni was reported from off the Golfo de Morrosquillo, Colombia, depth 100 m ( Daccarett & Bossio 2011). The 103 m depth of one MNHN lot is near the shallow record for the species.

Fusinus chocolatus ranges from French Guiana and Suriname northward to Trinidad and Tobago and St. Vincent in the Lesser Antilles and westward into the Caribbean Sea off northern Venezuela ( Hadorn & Rogers 2000) and Colombia ( Daccarett & Bossio 2011; Mallard & Robin 2017). A distributional map by Mallard and Robin (2017: 27) indicates the species ranging southeastward to Maranhão, Brazil, but we know of no records from Brazil. A long-dead shell from Guadeloupe figured as F. chocolatus by Mallard and Robin (2005: pl. 18), Massemin et al. (2009: 155), Mallard and Robin (2017: 27, fig. 1) and Lamy and Pointier (2017: 315, fig. 7a, b) does not seem to be this species. Numerous closely-spaced axial ribs on whorls of the spire of the Guadeloupe specimen are markedly arched at the posterior shoulder, unlike the fewer, more widely spaced axial ribs of F. chocolatus , and parts of its anterior outer lip and siphonal process are broken; determination of its true identity may require better material. A shell from off Los Monjes, Colombia that Mallard and Robin (2017: 27, fig. 3) figured as F. chocolatus is similarly suspect; atypical features include a wide, sinuous siphonal process and peripherally carinate whorls, unlike the narrow, straight siphon and rounded whorls of F. chocolatus .

Figures

FIGURES 5–16. Guianas Fusininae. 5–8. Lyonsifusus ansatus (Gmelin, 1791). 5–6. 163.8 mm, off Amapá, Brazil, R/V Oregon, depth 100–120 m, LC. 7–8. 162.4 mm, Suriname, depth 80 m, LC. 9–10. Lyonsifusus carvalhoriosi Macsotay & Campos Villarroel, 2001, 142.6 mm, off Cayenne, French Guiana, depth 64 m, LC. 11–12. Aristofusus benjamini Hadorn, 1997, 171.6 mm, CP4379, 06°33’N, 52°26’W, depth 130–131 m, MNHN IM-2013-56484. 13–14. Fusinus chocolatus (Okutani, 1983), 45.9 mm, CP4377, 06°36’N, 52°29’W, depth 157–162 m, MNHN IM-2014-6076. 15–16. Fusinus dilectus (A. Adams, 1856), 77.0 mm, off Paramaraibo, Suriname, R/V Oregon, RC.