Spurilla undetermined

Carmona, Leila, Lei, Bonnie R., Pola, Marta, Gosliner, Terrence M., Valdés, Ángel & Cervera, Juan Lucas, 2014, Untangling the Spurilla neapolitana (Delle Chiaje, 1841) species complex: a review of the genus Spurilla Bergh, 1864 (Mollusca: Nudibranchia: Aeolidiidae), Zoological Journal of the Linnean Society 170 (1), pp. 132-154 : 147

SPURILLA DUPONTAE SP. NOV.

( FIGS 3E , 5B , 6C–D )

Material examined

Holotype: LACM 3254 , dissected, 38 mm in length preserved, Bahamas, Stocking Island , collected by Anne DuPont, 13.iii.08.

Paratype: LACM 3255 , one specimen, dissected, 32 mm in length preserved, Stocking Island , Bahamas, collected by Anne DuPont, 13.iii.08 .

Type locality and habitat

Bahamas. Found in a sheltered harbour, on Padina sp.

Geographical distribution

So far, only known from the Bahamas.

Etymology

This species is dedicated to Anne DuPont, who collected the first specimens of this species.

External morphology ( Fig. 5B )

The body is elongate and slender, tapering gradually to the posterior end. The anterior foot corners extend into tentaculiform processes. The body colour is translucent pale brown overlaid with a conspicuous ochre or brownish reticulate pattern. Cream white spots are found all over the dorsum (from the head to the posterior end). Their density and size vary with the specimen.

The rhinophores, the oral tentacles, and the foot corners have the same colour as the rest of the body, with the brownish or ochre reticulate pattern. The rhinophores are perfoliate, bearing 16 lamellae, and are slightly shorter than the oral tentacles. The apices of the rhinophores are white. Some specimens have white-tipped oral tentacles.

The cerata are long, cylindrical, with round apices, and uniform in diameter throughout most of their length, with their tips curved inwards. They extend from behind the rhinophores to the posterior end. The cerata are arranged in up to seven arches of decreasing length towards the posterior end, with a distinct gap between them. Each arch contains between three and nine cerata, decreasing in size towards the foot. The ceratal apices are translucent white. White cream spots are present on the ceratal surface, although their density and size vary between individuals. The anus is cleioproctic and is located within the second right arch. The genital opening is situated among the cerata of the anteriormost group on the right.

Anatomy

The masticatory border of the jaws is smooth ( Fig. 6C ). The radular formulae are 10 × 0.1.0 (LACM 3255, 32 mm) and 21 × 0.1.0 (LACM 3254, 38 mm). The teeth are progressively smaller in the posterior region of the radula. The radular teeth are biarched, with up to 29 acutely pointed denticles on either side of the small and triangular central cusp ( Fig. 6D ). Oral and salivary glands were not examined.

The reproductive system is diaulic ( Fig. 3E ). The preampullary duct widens into a conspicuous ampulla that narrows again before dividing into the oviduct and vas deferens. The moderately thick vas deferens enters the wider proximal portion of the penial sac, which contains the unarmed penial papilla. The short oviduct connects to a folded and convoluted receptaculum seminis. The remaining portion of the oviduct departs from the base of the receptaculum and enters the female gland. The vagina opens ventral to the penis.

Remarks

Externally, S. dupontae sp. nov. is easily distinguishable from the remaining members of this genus by its conspicuous reticulate pattern covering the whole body, including the entire rhinophores. Although this pattern is found to some extent in all Spurilla species , in S. dupontae sp. nov. it is more evident and is visible on the rhinophores. All other species of Spurilla have similar morphology in the receptaculum seminis ( Fig. 3A–D ), whereas in S. dupontae sp. nov. it is folded and convoluted ( Fig. 3E ).

Figures

Figure 3. Reproductive system: A, Spurilla neapolitana, specimen from Azores (CASIZ 072582), scale bar = 1 mm; B, Spurilla sargassicola, specimen from the Bahamas (MNCN 15.05/63468), scale bar = 0.5 mm; C, Spurilla braziliana, specimen from Brazil (MNCN 15.05/63471); D, Spurilla onubensis sp. nov., holotype (MNCN 15.05/60081), specimen from Spain, Huelva, scale bar = 0.5 mm; E, Spurilla dupontae. sp. nov., holotype (LACM 3254), specimen from the Bahamas, Stocking Island, scale bar = 1 mm. Abbreviations: am, ampulla; fgm, female gland mass; ps, penial sac; rs, receptaculum seminis; va, vagina; vd, vas deferens.

Figure 5. Photographs of living animals. A, Spurilla onubensis sp. nov. specimen from Southern Spain, Huelva, photo by Sergio García-Gómez, (MNCN 15.05/60081); B, Spurilla dupontae. sp. nov. specimen from the Bahamas, Stocking Island, photo by Anne DuPont (LACM 3254).

Figure 6. Scanning electron photographs. A, B, Spurilla onubensis sp. nov. (MNCN 15.05/60082), specimen from Spain, Huelva; A, detailed view of the masticatory border, scale bar = 20 μm; B, radular teeth, scale bar = 100 μm. C, D, Spurilla dupontae. sp. nov. (LACM 3254), specimen from the Bahamas, Stocking Island; C, jaws, scale bar = 500 μm; D, radular teeth, scale bar = 200 μm.