Trapania sp. 1

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, Zoological Journal of the Linnean Society 196, pp. 270-313 : 305

publication ID	https://doi.org/ 10.1093/zoolinnean/zlac009
publication LSID	lsid:zoobank.org:pub:C288BAB2-A92C-4F13-B04D-D6D4510461F5
DOI	https://doi.org/10.5281/zenodo.7043824
persistent identifier	https://treatment.plazi.org/id/03E487E4-FFBB-FB0B-EB94-FCBCFBC5FB6D
treatment provided by	Plazi
scientific name	Trapania sp. 1
status

Treatment

Trapania sp. 1 Pittman & Fiene, 2021.

Type material: Holotype: CASIZ 189444 , one specimen, dissected and sequenced, Airport Beach , Maui, Hawaiʻi, USA, 12–18 m depth, 19 February 2012, collected by Cory Pittman.

Other material: Trapania sp. cf. kanaloa, CASIZ 199250, one specimen, sequenced, preserved length 1.5 mm, Koloa Landing , Kauaʻi, Hawaiʻi, USA, 8–14 m depth, 30 May 2014, collected by Cory Pittman.

Type locality: Airport Beach , Maui, Hawaiʻi, USA .

Geographical distribution: Known only from the Hawaiian Islands.

Etymology: The Hawaiʻian god Kanaloa is often symbolized by a squid or octopus form. This species is also found in association with beds of the alga Halimeda kanaloana Vroom, 2006 , which is named for the same deity. It is a noun in apposition.

External morphology: The living animal is 3 mm in length ( Fig. 12E View Figure12 , upper photo). The body is brown coloured with a dense frosting of small, white and darker brown punctations and brown patches. The rhinophores are thick and bulbous with approximately eight lamellae and a white apex. They have the same cream and brown pigment as the rest of the body. The extra-rhinophoral and extra-branchial appendages are thin with a clubshaped apex and are also brown and cream, with fine opaque white punctations. The gill is small consisting of three simply pinnate branches. The posterior end of the foot is short and blunt with brown and whitish mottling. Buccal mass: The buccal mass is muscular with a moderately developed buccal pump on the dorsal surface. Inside the anterior portion of the mass is a pair of well-developed jaws. The jaws contain several rows of acutely pointed, cylindrical jaw elements that are tightly packed together with a few gaps between them ( Fig. 18A View Figure 18 ). The radular formula of the holotype is 19 × 1.0.1 ( Fig. 18B View Figure 18 ). The older teeth ( Fig. 18C View Figure 18 ) are much smaller than the newer ones ( Fig. 18D View Figure 18 ) and the radula widens towards the more newly developed teeth. The teeth bear numerous relatively equal-sized denticles with the smallest ones being found on the inner edge of the tooth. There are approximately six to eight denticles on the inner side of the much larger primary cusp, and one to three much smaller 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. 16C View Figure 16 ). The pre-ampullary duct is narrow and joins the post-ampullary duct distally to the ampulla. The pyriform ampulla narrows to the point where it divides into the short oviduct and elongate vas deferens. The oviduct enters the female gland mass. The vas deferens is initially narrow and widens into a slightly convoluted, glandular prostatic portion and gradually transitions into the wide, muscular ejaculatory portion that abruptly narrows and makes a sharp turn prior to expanding into the wide penial sac. The penial sac terminates at the gonopore adjacent to the vagina. The vagina is equally wide throughout its length. Immediately prior to its entrance into the large spherical bursa copulatrix is a short branch of the receptaculum duct that leads to the smaller, spherical receptaculum seminis. Emerging from the receptaculum duct is a uterine duct that 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, the ABGD analyses and the bPTP analysis show that Trapania kanaloa is a distinct species separate from its similarly coloured sisterspecies T. euryeia . Externally, T. euryeia has a darker body colour than T. kanaloa with more brown pigment and much larger, more regular white punctations. In our ABGD and bPTP analyses, the holotype of T. kanaloa collected from Maui is potentially distinct from the specimen we call T. sp. cf. kanaloa ( CASIZ 199250) due to a high genetic divergence of 4.3% in the mitochondrial gene COI ( Table 3 View Table 3 ) and a genetic divergence of 2.6% in the mitochondrial gene 16S ( Table 4 View Table 4 ). This specimen was collected from Kauaʻi and was previously considered to be a variant of T. euryeia by Pittman & Fiene (2021) due to its pale external coloration; however, this specimen is probably immature (preserved length = 1.5 mm) and the photo of the living animal ( Fig. 12E View Figure12 , lower photo) indicates that it has less concentrated brownish pigment. Owing to its small size we were not able to dissect this specimen to compare its anatomy. In contrast, the interspecific variation between T. kanaloa and T. euryeia from the Philippines is 9.3% in the COI gene ( Table 3 View Table 3 ) and 5.5% in the 16S gene ( Table 4 View Table 4 ) The interspecific variation between T. sp. cf. kanaloa and T. euryeia is similar, i.e. 9.3% in the COI gene ( Table 3 View Table 3 ) and 5.7% in the 16S gene ( Table 4 View Table 4 ), indicating that the T. sp. cf. kanaloa specimen is not T. euryeia . Further study of T. kanaloa , with additional representatives from Hawaiʻi, is necessary to determine whether one or two species are present across the Hawaiʻian Archipelago. Similarly, comparisons with additional specimens of T. euryeia from a broader geographical area are necessary to better understand the genetic variation present within and between these two species. Present data indicate that pale specimens from Hawaiʻi should be regarded as T. kanaloa . Pittman & Fiene (2021) also show a photo of a darker specimen of T. euryeia from Hawaiʻi that more closely resembles specimens from elsewhere in the Indo-Pacific, and the question remains as to whether this is conspecific with other specimens of T. euryeia from the western Pacific. The radular teeth previously described for T. euryeia are similar to those found here in T. kanaloa . There appear to be significant differences in the reproductive systems of T. kanaloa and T. euryeia . In T. kanaloa , the prostatic portion of the vas deferens is less convoluted than in T. euryeia . Most significantly, the vagina of T. kanaloa is of uniform diameter throughout its length, whereas T. euryeia has a glandular collar present around the vagina near its junction with the penial sac, which is absent in T. kanaloa .