Fasciolaria guyanensis Lyons & Snyder 2016
- Dataset
- Fasciolariidae (Gastropoda: Neogastropoda) of French Guiana and nearby regions, with descriptions of two new species and comments on marine zoogeography of northeastern South America
- Rank
- SPECIES
Classification
- kingdom
- Animalia
- phylum
- Mollusca
- class
- Gastropoda
- order
- Neogastropoda
- family
- Fasciolariidae
- genus
- Fasciolaria
- species
- Fasciolaria guyanensis
description
(Figures 1 – 2)
diagnosis
Diagnosis. Shell large, to ~ 250 mm sl, sub-bullate, with tall spire, rapidly expanding whorls, and moderately long, slender siphonal process. Protoconch globose, smooth. Teleoconch with about 7 broadly convex whorls constricted at suture, with conspicuous anterior sutural ramp bearing prominent subsutural grooves; shell surface otherwise smooth except for fine spiral lines and bands, most interrupted but some complete on final ½ whorl. Aperture subovate, constricted posteriorly; outer lip arcuate, slightly flexed at intersection with sutural ramp, forming shallow sinus at junction with parietal shield; edge of outer lip bearing small blackish-brown or orange-brown denticles representing termini of spiral bands of body whorl; inside of outer lip with> 50 fine emergent lirae extending nearly to lip edge; parietal shield adherent, thin, glazed, sometimes with faint callus near posterior end; columella concave, with 3 oblique folds (including entrance fold) near junction with siphonal process. Shell background color salmon pink, with 3 bands of irregular red, dark tan or orange-brown blotches encircling anterior, middle and posterior portions of body whorl; single similar bands of irregular blotches on posterior portions of spire whorls; interior white. Types. Holotype: lv, 109.8 mm, off Guyane, 40 m, IM- 2000 - 30193, ex DL; Paratypes: French Guiana — 1 - dd, 158.0 mm, same data as holotype, IM- 2000 - 30194; 1 - lv, 9.3 mm, GUYANE sta. CP 4352, 05 ° 13.9 ’ N, 51 ° 41 ’ W, depth 60 m, 28 July 2014, IM- 2013 - 55965; 1 - lv, 116.5 mm (siphonal canal broken), GUYANE sta. CP 4386, 05 ° 38 ’ N, 52 ° 29.2 ’ W, 46 – 47 m, 0 5 Aug 2014, IM- 2013 - 56591. Guyana — 2 - lv, 100.4 and 117.3 mm, off Berbice County, 50 m, muddy sand, ANSP 465322. Suriname — 2 - lv, 93.5 and 132.3 mm, off Suriname, shrimp trawl, ~ 100 m, LC. Brazil — 1 - dd, 167.4 mm, off São Luiz, Maranhão, shrimp trawl, 20 – 30 m, LC.
discussion
Remarks. Lyons and Snyder (2016: 4) distinguished F. guyanensis from congeners F. tulipa (Linnaeus, 1758) (range: North Carolina to Central America and the Lesser Antilles) and F. hollisteri Weisbord, 1962 (range: continental shelf of Caribbean South America, i. e., Colombia, Venezuela and the southern Netherlands Antilles) principally by the absence of axial riblets on its large, globose protoconch; both of the other species have smaller, more tapered protoconchs bearing distinct axial riblets. Differences in sutural ramp morphology and spire angle among the species were also discussed. Couto et al. (2016: 310, 314, 315) included tissue from the 9.3 mm paratype of F. guyanensis (IM- 2013 - 55965; as Fasciolaria sp.) in a study of molecular phylogeny within Fasciolariidae. Using nuclear and mitochondrial genes, they compared F. guyanensis to F. tulipa from Guadeloupe, French Antilles and F. bullisi Lyons, 1972 from Florida. Results showed levels of divergence between F. guyanensis, F. tulipa and F. bullisi similar to those seen with other closely related species; their maximum likelihood analysis shows F. guyanensis sister to F. tulipa, but their Bayesian analysis shows it sister to F. bullisi, although with weak support (Lyons & Snyder 2016: 5).
materials_examined
Other material. French Guiana — 2 - dd, 7.0 and 8.3 mm, GUYANE sta. CP 4352, 05 ° 13.9 ’ N, 51 ° 41 ’ W, depth 60 m, 28 July 2014; 2 - dd, 35.8 and 147.8 mm, GUYANE sta. CP 4381, 06 ° 31 ’ N, 52 ° 26 ’ W, 114 – 118 m, 0 4 Aug 2014; 1 - dd, 15.3 mm, GUYANE sta. CP 4382, 06 ° 27.8 ’ N, 52 ° 25.5 ’ W, 93 – 95 m, 0 4 Aug 2014; 5 - dd, 6.8, 6.8, 7.5, 9.2 and 19.6 mm, GUYANE sta. CP 4386, 05 ° 38 ’ N, 52 ° 29.2 ’ W, 46 – 47 m, 0 5 Aug 2014; 1 - dd, 61.5 mm, GUYANE sta. CP 4402, 06 ° 18 ’ N, 52 ° 13.3 ’ W, 95 – 97 m, 0 8 Aug 2014; 1 - dd, 134.5 mm, G 0 sta. 16, 05 ° 10.7 ’ N, 51 ° 03.8 ’ W, 80 – 82 m, 19 Apr 1999; 1 - lv, 151.1 mm, G 0 sta. 17, 05 ° 06.3 ’ N, 51 ° 43.7 ’ W, 70 – 68 m, 19 Apr 1999; 1 - lv. 123.4 mm, “ French Guyana, ” 30 – 40 m, LC. Brazil — 1 - lv, 140.8 mm, 1 - dd, 120.8 mm, off Amapá, trawled, R / V Oregon, 4 / 1960 [!], KV; 1 - dd, 175.0 mm, off Bragança, Pará, trawled, 40 – 80 m, LC.