Trapania kamagong 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 kamagong

description: TRAPANIA KAMAGONG SP. NOV.
(FIGS 12D, 16B, 17)
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: E8973F5A-119C-487B-9538-74B21D15ACC6.
Trapania sp. 3 Gosliner et al., 2008: 137, second photograph from the bottom; Gosliner et al., 2018: 59, lower-right photo.
Trapania sp. 2 Gosliner et al., 2015: 140, upper-left photograph.
Type material: Holotype: NMP 041336, originally CASIZ 208585 A, one specimen, dissected and sequenced, Puerto Galera (13.51350 °N 120.95833°E), Mindoro, Mindoro Oriental Province, Philippines, 6–20 m depth, 29 March 2015, collected by P. J. Aristorenas. Paratype: CASIZ 177526, one specimen, sequenced, Mainit Point (13.68640°N 120.895413°E), Mabini (Calumpan Peninsula), Batangas Province, Luzon Island, Philippines, 22.7 m depth, 21 March 2008, collected by T. M. Gosliner, A. Valdes, M. Pola, L. Witzel, B. Moore and A. Alejandrino.
Ty p e l o c a l i t y: P u e r t o G a l e r a (1 3. 5 1 3 5 0 ° N 120.95833°E), Mindoro, Mindoro Oriental Province, the Philippines.
Geographical distribution: Known only from the Philippines.
Etymology: Kamagong is the Tagalog name for the velvet apple, Diospyros discolor Willd. (Ebenaceae), a species of persimmon tree found in the Philippines and Taiwan. It refers to the distinguishing dark-tipped, extra-rhinophoral and extra-branchial appendages of this species.
External morphology: Living animal 15 mm (Fig. 12D). It has an opaque grey body covered dorsally with speckled red-brown colour characterized by small and large blotches of missing pigmentation. Notable blotches reside laterally below the rhinophores, below the gill plum and at the posterior portion of the foot. Extra-rhinophoral and extra-branchial appendages lack coloration from base to the tip, which has the same red-brown coloration as the body. Rhinophores, eight to ten lamellae and a pointed tip, are uniformly wide along their length and the same colour as the red-brown body, except for grey tip. Oral tentacles are coloured at their base and opaque grey at the tip. Similarly, the anterior margins of the foot, which extend laterally as elongate appendages, are coloured at their base and opaque grey at their tip. The gill plum is prominent and a lighter brown than the body. Buccal mass: The buccal mass is muscular with a moderately enlarged buccal pump on the dorsal surface. Inside the anterior portion of the mass is a pair of well-developed jaws. The jaws contain a row of acutely pointed and stubby jaw elements of various sizes that are tightly packed together with a few gaps between them (Fig. 17A). The radular formula of the holotype is 23 × 1.0.1. The older teeth are much smaller (Fig. 17B) than the newer ones (Figs. 17C, D) and the radula widens gradually towards the more newly developed teeth. The teeth bear numerous denticles with the smallest ones being found on the inner edge of the tooth. There are approximately four to 15 denticles on the inner side of the much larger primary cusp, and one to two denticles on the outer side of the cusp. The older teeth have fewer denticles than the more recently developed ones.
Reproductive system: The mature reproductive system is triaulic (Fig. 16B). The cylindrical ampulla is narrow and short from the distal end where it connects to the ovotestis to where it merges into post-ampullary duct. The post-ampullary divides at its base into a short oviduct and vas deferens. The oviduct enters the female gland mass. The vas deferens is initially narrow and widens into a convoluted, glandular prostatic portion with multiple turns before abruptly transitioning into the narrow, muscular ejaculatory portion that is continuous with the short, bulbous penial sac. The penial sac terminates at the gonopore adjacent to the vagina. The vagina is equally narrow at its opening until its junction with the large, spherical bursa copulatrix. A narrow receptaculum duct leads from the bursa copulatrix to the spherical receptaculum at the division of the 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: Our molecular phylogeny moderately (BI) or weakly (ML) places Trapania tamaraw at the base of a clade that includes a well-supported clade with T. stegodon, T. sp. ‘Anilao’ and T. kamagong. However, our ABGD and bPTP analyses support T. tamaraw as a distinct species due to a strong divergence of 15.8% in the COI gene between T. tamaraw and T. stegodon, 14.8%/7.6−7.8% in the COI /16S genes between T. tamaraw and T. kamagong, and 13.6%/7.9% between T. tamaraw and T. sp. ‘Anilao’ (Tables 3, 4). The closest related species to T. stegodon include T. sp. ‘Anilao’ and T. kamagong; which have a smaller COI genetic divergence of 6.3% between T. stegodon and T. sp. ‘Anilao’ and 6.6–7.0% between T. stegodon and T. kamagong (Table 3). This species also has a distinctive patchy colour pattern of creamy yellowish to tan interspersed with dark-brown blotches. The colour pattern is similar to that of T. euryeia (see: Gosliner & Fahey, 2008) and Trapania toddi Rudman, 1987, with the exception that both of these species have lighter punctations in the dark blotches that are absent in T. tamaraw. Also, T. tamaraw is a member of a different clade than T. euryeia studied here. Internally, T. tamaraw has huge jaws, as compared to those found in T. euryeia. The reproductive system of T. tamaraw differs from that of T. euryeia and T. toddi. The pre-ampullary duct of T. tamaraw (Fig. 4I) enters the distal end of the ampulla, whereas it enters subdistally in T. toddi (Rudman, 1987: fig. 4D) and proximally in T. euryeia (Gosliner & Fahey, 2008: fig.19). Also, T. euryeia has a vaginal collar (Gosliner & Fahey, 2008: fig. 19) that appears to be glandular and is absent in T. toddi and T. tamaraw.
Trapania tamaraw, T. stegodon, T. sp. ‘Anilao’ and T. kamagong form a weakly supported clade that represents a species complex. When T. tamaraw is compared to the other members of the clade in which it is placed, there are significant distinctive morphological characteristics for the four species in this clade. With respect to external coloration, T. tamaraw is smaller (about 4 mm, whereas the other three species are approximately 15 mm in length) and is unique in having well-separated dark-brown and yellowish patches and lacks the opaque white spotting found in T. stegodon, T. kamagong and T. sp. ‘Anilao’. In T. stegodon, T. kamagong and T. sp. ‘Anilao’, the brownish body pigmented areas are interrupted by small, irregularly shaped white patches. The primary external differences between T. stegodon, T. kamagong and T. sp. ‘Anilao’ are in the pigment pattern found on the extra-rhinophoral and extra-branchial appendages. In T. stegodon, the extra-rhinophoral and extra-branchial appendages are uniformly whitish yellow, whereas the appendages of T. kamagong are the same colour but have a brown apex. The preserved pigmentation pattern of T. sp. ‘Anilao’ are a uniform continuation of the body coloration with the exception of medial whitish transverse band and a white apex.
The jaws of the four species also differ. In T. tamaraw, there are massive jaws that bear a single row of large, acutely-pointed denticles along the masticatory margin. In T. stegodon, the jaws bear several rows or acutely pointed rodlets over much of the surface of the jaws; in T. sp. ‘Anilao’ there is a single row of rounded rodlets along the margin; in T. kamagong, there are two to three rows of rodlets on the margin of the jaws. Additional radular characters also separate the four members of this species complex. The radular teeth of T. tamaraw are more strongly arched along their anterior surface than in the other three species. Also, T. tamaraw has much reduced denticles on the outer side of the primary cusp, where the denticles are either entirely absent or are present as a series of up to eight minute denticles. Both T. stegodon and T. kamagong have denticles of irregular lengths on the inner side of the primary cusp, whereas they are more similar in size in T. sp. ‘Anilao’. In T. stegodon the primary cusp is narrower and straighter than that of T. kamagong, where the primary cusp is broader at the base and is more curved inwardly.
The reproductive systems of the four species forming this species complex bear significant differences. In T. tamaraw (Fig. 4I), the pre-ampullary duct enters the distal end of the ampulla, while it enters far more proximally in T. stegodon (Fig. 4J), T. sp.‘Anilao’ (Fig. 16A) and T. kamagong (Fig. 16B). In T. tamaraw the prostatic vas deferens does not narrow into a distinct ejaculatory segment, whereas the other three species all have a distinct narrowing between the prostate and penial sac. The penial sac of T. tamaraw (Fig. 4I), T. stegodon (Fig. 4J) and T. kamagong (Fig. 16B) is relatively short, whereas it is much longer in T. sp. ‘Anilao’ (Fig. 16A).
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 302-305, DOI: 10.1093/zoolinnean/zlac009, http://zenodo.org/record/7037746