Trapania lemanioides Smirnoff & Donohoo & Gosliner 2022, SP. NOV.
Creators: name: Smirnoff, Dimitri S.
name: Donohoo, Samantha A.
name: Gosliner, Terrence M.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Nudibranchia
Goniodorididae
Trapania
Trapania lemanioides

description: TRAPANIA LEMANIOIDES SP. NOV.
(FIGS 2D, E, 4D, 7)
Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 172793CC-C647-44F6-8926-8AB7593490B2.
Trapania sp. 2 Gosliner et al., 2018: 59, top-right photograph.
Type material: Holotype: NMP 041335, originally CASIZ 208433, one specimen, partially dissected and sequenced, Manila Channel (13.52230°N 120.94850°E), Puerto Galera, Mindoro Oriental Province, Mindoro, Philippines, 3−23 m, 13 April 2015, collected by P. J. Aristoreanas. Paratypes: CASIZ 221979, one specimen, sequenced, Romblon Island (12.53267°N 122.24998°E), Romblon Province, Philippines, 7–16 m depth, 05 April 2017, collected by Joseph Maestro. CASIZ 222066, one specimen, dissected and sequenced, Romblon Island (12.55660°N 122.24940°E), Romblon Province, Philippines, 4–21 m depth, 04 April 2017, collected by Joseph Maestro.
Ty p e l o c a l i t y: M a n i l l a C h a n n e l (1 3.5 2 2 3 0°N 120.94850°E), Puerto Galera, Mindoro Oriental Province, Mindoro, the Philippines.
Geographical distribution: Known only from the Philippines.
Natural history: Trapania lemanioides is often associated with large colonies of the octocoral genus Lemnalia Gray, 1868. It is cryptically coloured on these soft coral colonies. It does not appear to feed on the soft coral but is frequently associated with it.
Etymology: This species named for its resemblance to the octocoral genus Lemnalia, with which this species is often associated.
External morphology: Living animals are 3−5 mm (Fig. 2D, E). Body opaque, slightly pink and covered unevenly in a frosting of white pigmentation. The rhinophores, evenly wide along their length, have four to five lamellae with a pointed tip and are particularly white at their apex. The bipinnate gill plume is small and white, consisting of three branches. Both extrarhinophoral and extra-branchial appendages are average sized and particularly white. The anterior margins of the foot extend laterally as elongate appendages are more translucent than the rest of the body and are slightly longer than the oral tentacles. The long, conical oral tentacles and oral veil are particularly white. The white pigmentation on the dorsal ridge of the most posterior portion of the foot appears as if it is clumpy.
Buccal mass: The buccal mass is muscular with a moderately developed buccal pump on the dorsal surface. It was not possible to discern any details of the structure of the jaws. The radular formula in the specimen CASIZ 222066 is 16–17 × 1.0.1 (Fig. 7A) with one additional tooth being present on the right side of the radula. The left side of the radula appears to have one additional tooth, hence the variation in formula. The radula of the holotype was not removed. The older teeth (Fig. 7B) are much smaller than the newer ones and the radula widens towards the more newly developed teeth (Fig. 7C, D). The teeth bear numerous evenly graded, elongate denticles with the smallest ones being found on the inner edge of the tooth. There are approximately three to six denticles on the inner side of the much larger, narrow primary cusp and one denticle on the outer side of the cusp. The older teeth have fewer denticles than the more newly developed teeth.
Reproduction system: In the holotype NMP 041335, the mature reproductive system is triaulic (Fig. 4D). The reproductive system of the paratype (CASIZ 222066) was immature. The narrow pre-ampullary duct enters the spherical ampulla at its base, adjacent to the vas deferens. The oviduct departs the ampulla on the other side of the vas deferens enters the female gland mass. The vas deferens is equally sized throughout its length until a sharp turn where it transitions into an equally sized muscular ejaculatory portion that is continuous with the wide penial sac. The penial sac terminates at the gonopore adjacent to the vagina. The short vagina is uniformly narrow throughout its length and joins the small, pyriform bursa copulatrix and short narrow receptaculum duct. The receptaculum duct joins the equally small pyriform receptaculum seminis near the division of the long uterine duct, which enters the female gland mass. The female gland mass is composed of the large mucous gland and the smaller albumen and membrane glands.
Remarks: In our molecular phylogeny, Trapania lemanioides is sister to a clade composed of T. circinata and T. naeva. Our ABGD and bPTP analyses reveal a strong genetic divergence of 13.9–15.7% in the COI gene and 10.3−10.6% in the 16S gene between T. lemanioides and T. naeva and 12.2−14.0% in the COI gene between T. lemanioides and T. circinata, while intraspecific variation ranged between 0.9 and 1.5% in the three Philippine specimens of T. lemanioides studied here (Tables 3, 4). Morphologically, T. lemanioides is distinct from T.circinata and T. naeva. The latter two species have black markings on the rhinophores, oral tentacles, extrarhinophoral appendages extra-branchial appendages and gill that are not present in T. lemanioides, which has a uniformly, frosted white or pinkish white coloration. Additionally, T. naeva has large, black spots on the body. The only other species that has a largely uniform white coloration is Trapania armilla Gosliner & Fahey, 2008. However, this species has a distinctive dark ring on the oral tentacles and large tubercles on the body, which are both absent in T. lemanioides. The radular teeth of T. lemanioides are similar to those of T. circinata and T. naeva, with widely separated denticles and a single, large cusp near the outer margin of the tooth. Both T. circinata and T. naeva have more denticles (eight to nine and seven to nine, respectively) inside the large cusp, whereas there are only three to six in T. lemanioides. In all three species, the ampulla is rounded and the pre-ampullary duct enters the ampulla near its distal end. In T. circinata and T. naev, there is a narrowing of the ejaculatory duct prior to its entry into the wide portion of the penial sac. In T. lemanioides, the prostatic and ejaculatory portions of the male duct and penial sac are all of uniform diameter. In both T. naeva and T. lemanioides, the distal portion of the vagina is much wider than the proximal portion, while in T. circinata the vagina is uniformly narrow throughout.
description: Published as part of Smirnoff, Dimitri S., Donohoo, Samantha A. & Gosliner, Terrence M., 2022, Extra-branchial processes manifest extra diversity: systematics of the genus Trapania (Nudibranchia: Goniodorididae) and nine new species descriptions, pp. 270-313 in Zoological Journal of the Linnean Society 196 on pages 288-289, DOI: 10.1093/zoolinnean/zlac009, http://zenodo.org/record/7037746