Cyerce willetteorum Moreno & Rico & Middlebrooks & Medrano & Valdés & Krug 2024, sp.nov.
Creators: name: Moreno, Karina
name: Rico, Diane M.
name: Middlebrooks, Michael
name: Medrano, Sabrina
name: Valdés, Ángel A.
name: Krug, Patrick J.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Sacoglossa
Hermaeidae
Cyerce
Cyerce willetteorum

description: Cyerce willetteorum sp.nov.
(Figs 1–3, 5, 8F, 17)
ZooBank registration: lsid:zoobank. org:act: B2309FF2-4BF7-4317-BE5F-5398AB298F30
Type material
Holotype: Stirrup Cay, Bahamas, July 2001, 2 mm preserved length (LACM 3844; isolate 07Stir01).
Range
Great Stirrup Cay, Bahamas (present study).
Description
External morphology: No photograph was taken of the live specimen, hence no description of external morphology is possible at this time.
Internal morphology: Radula of holotype (LACM 3844, isolate 07Stir01) with six teeth on ascending limb and seven teeth on descending limb (Fig. 17A). Teeth shallow, bent at an angle of 18°, tapering to pointed tip; 97 µm in length (Fig. 17B). Row of nine denticles along each cutting edge, irregular in shape and width; narrow at base, widening to a curved edge, ≤ 2.5 μm wide. Denticles narrower, more rectangular near tip (Fig. 17B). Partial ascus with four pre-radular teeth (Fig. 17C).
Penis with curved, wide stylet, narrowing gradually from embedded base, 120 µm long; oval opening at wide tip (Fig. 8F).
Ecology
Collected from Pe. capitatus.
Etymology
Named in joint honour of Dr Demian Willette, who contributed specimens to this work and helped P.J.K. to initiate studies of sacoglossan biodiversity, and his brother Darian Willette, a devoted naturalist lost at too young an age.
Remarks
Only a single exemplar of C. willetteorum was sampled over the 15-year duration of this study of Western Atlantic sacoglossans. However, the lone specimen was supported as a distinct species by all methods of molecular species delimitation. Although the external morphology could not be described at this time, the penial stylet was distinct from the other complex members, less curved and shorter than C. nicholasi but more curved and longer than any other newly described species. The radular denticles were also distinctive, with an irregular shape and curved edge not observed in any other species. Given the genetic support for the holotype as a separate species and the distinctive characteristics of the internal anatomy, we elected to name the species to clarify the diversity of the Caribbean Cyerce spp. and to facilitate future studies of the biology of this rare taxon.
This was the only species collected from Pe. capitatus, although C. cf. cristallina associates transiently with Pe. capitatus at night (M. Charteris, unpublished data). Algal congeners Pe. dumetosus and Pe. lamourouxii were used as hosts by four other complex members and have thicker filaments than Pe. capitatus on the ‘shaving brush’ portion of the algal thallus. However, extensive collections of Pe. capitatus made elsewhere in the Caribbean did not yield specimens of Cyerce, leaving it unclear whether Pe. capitatus is a preferred host of C. willetteorum or was merely the more locally abundant Penicillus sp. at the type locality. Further study is needed to understand the basis of host specificity within the C. antillensis complex.
description: Published as part of Moreno, Karina, Rico, Diane M., Middlebrooks, Michael, Medrano, Sabrina, Valdés, Ángel A. & Krug, Patrick J., 2024, A cryptic radiation of Caribbean sea slugs revealed by integrative analysis: Cyerce ' antillensis' (Sacoglossa: Caliphyllidae) is six distinct species, pp. 940-979 in Zoological Journal of the Linnean Society 200 (4) on pages 968-970, DOI: 10.1093/zoolinnean/zlad111, http://zenodo.org/record/11240925