Hoplodoris desmoparypha in Bergh 1880
Creators: name: Donohoo, Samantha A.
name: Gosliner, Terrence M.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Nudibranchia
Discodorididae
Hoplodoris
Hoplodoris desmoparypha

description: Hoplodoris desmoparypha Bergh, 1880
(Figs. 7A, 8A, 9, 10A, 11 A–B)
Hoplodoris desmoparypha Bergh, 1880:51–56, plate C, figs 5–9, plate F, figs 1–18. Bergh, 1905:113–115, plate XIV, figs 41–46, plate XV, figs 1–2. White, 1950: 99–100.
Asteronotus raripilosa — Dayrat 2010: 174–186, figs 191D–F, 192B, 197F, 200B, 202C, 203B.
Material examined. CASIZ 309550, one specimen, dissected, foot subsampled for molecular analyses, Ngermutidech, 7.31233° N 34.5187° E, Koror Island, Palau, 1m depth, 22 May 1996, Coral Reef Research Foundation. CA-SIZ 70066, one specimen, foot subsampled for molecular analyses; this specimen was dissected by Dayrat (2010) prior to the present study and re-identified as Asteronotus raripilosa by B. Dayrat. Seragaki Beach, 26.50667° N 127.87667° E, Maeki-zaki, Okinawa, Ryukyu, Japan, 25 Feb 1989, R. F. Bolland.
External morphology. The living animals (Fig. 7A) are oval in shape, approximately 55 mm in length, and found along exposed sand bars during low tide at approximately 1m in depth. The body color is tan with random irregularly shaped darker brown spots; numerous light-brown papillae with a few short random branches along a single stem; light-brown and reddish-brown tubercles (Fig. 8A); an irregular white patch along the gill pocket; and irregular dark brown blotches along the center and edge of the mantle. The underside of the mantle is tan with small to medium brown blotches surround the foot. Around the brown blotches are random dark brown flecks. A wide band of light brown specks in semi-irregular patches is offset from the mantle’s edge. The gill surrounds the anus and consists of six purplish-brown tripinnate branchial leaves with purplish-brown rachis and light brown tips. The gill pocket contains six lightly crenulated lobes with similar coloration to the rest of the body, as well as numerous papillae. The rhinophores are perfoliate with 15–20 light-brown lamellae with scattered brown spots. The two rhino-phoral sheaths are irregularly crenulated with similar coloration and papillae to the gill pocket and body. The foot is broad, anteriorly notched, with tan coloration and numerous brown flecks. Flat, slightly rounded triangular-shaped oral tentacles are present laterally on either side of the labial region and mouth.
Internal morphology. Buccal mass and radula. The buccal mass is muscular and anteriorly connects to a thin labial cuticle which has semi-elongate jaw rodlets (Fig. 9A). The radula is composed of predominantly hamate teeth and the radular formula is 39 × 61.0. 61 in the specimen CASIZ 309550. The inner lateral teeth (Fig. 9B) are short with a broad base and a curved cusp. Some of the inner teeth have one to two triangular denticles on the outer edge of the cusp. The middle lateral teeth (Fig. 9C) are larger with a broader base and more elongate cusp with one to three triangular denticles present on the outer edge of most teeth. The outer lateral teeth (Fig. 9D) are also large, but have a much shorter, rounder cusp than the middle lateral teeth; however, the outermost two teeth are reduced and semi-fimbriate. Most of the outer lateral teeth have one to three denticles on the outer edge of the cusp.
Reproductive system. Due to immature size, the reproductive system of the dissected specimen CASIZ 309550 is small and semi-underdeveloped; however, the reproductive organs were large enough to identify and tentatively describe. An elongate ampulla quickly narrows into the vas deferens and a short oviduct (Fig. 10A). The vas deferens enter the prostate, which expands into an elongate, muscular ejaculatory portion that narrows distally into the penis which shares a common genital atrium with the vagina and accessory gland. The penis is armed with numerous conical penial spines which have an irregular lightly scalloped edge (Fig. 11A). A narrow, elongate vagina enters an irregular, but spherical-shaped bursa copulatrix. A short duct connects near the base of the bursa to a much smaller receptaculum seminis. The uterine duct connects to the base of receptaculum and enters the female gland mass. An ovate, semi-irregular accessory gland is connected to the common genital atrium by a narrow, elongate duct. Within the base of the accessory gland is a slightly curved, but under-developed accessory spine with a semibroad base (Fig. 11B).
Geographical distribution. Palau (Bergh, 1880) to Indonesia (Bergh, 1905).
Remarks. Our molecular phylogeny, the ABGD analysis, and the bPTP analysis show that H. desmoparypha is a distinct species separated from Asteronotus by a divergence of 16.47–21.01% with intraspecific variation of 0.16% difference in the COI gene between specimens from the type locality of Palau and a specimen from Japan. Externally, the body coloration of living H. desmoparypha from the type locality of Palau was not described by Bergh (1880), but there is some variation in body color between living specimens from Palau and those from Japan studied here. Hoplodoris desmoparypha from Palau (CASIZ 309550) has a tan body color with various irregularly shaped brown and white patches, while the individual from Japan (CASIZ 70066) has a white body color and dark brown irregularly shaped patches. The tubercles and papillae are supported by a network of spicules as noted by Bergh (1880, plate F, fig. 18) and the shape of both are similar between specimens; however, the number of retained papillae post preservation varies between specimens (Dayrat 2010, figs. 191D–F). The oral tentacles, gills, and rhinophores are also similar between specimens; but, the younger CASIZ 309550 has fewer rhinophoral lamellae. The radular teeth in CASIZ 309550, closely resemble the size and shape of the radular teeth illustrated in Bergh (1880, plate F, figs. 1–4); however, Bergh’s illustrations are missing the triangular denticles found along most of the middle and outer lateral teeth, as well as the semi-fimbriate nature of the outermost tooth. Since CASIZ 309550 is immature, the radular formula was only 39 × 61.0.61; while, in the larger, adult H. desmoparypha the radular formula was 50 × 90.0. 90 in the specimen CASIZ 70066 (Dayrat 2010, fig. 197F).
The reproductive system in CASIZ 309550 is slightly reduced and underdeveloped. The relative size and shape of the various parts of the system still resemble the reproductive system drawn and described for H. desmoparypha in Bergh (1880) and for the adult specimen CASIZ 70066 in Dayrat (2010, fig. 200B). The ampulla studied here is not as long, convoluted, or looped as seen in Dayrat (2010). The prostate is also not as well differentiated into the two distinct sections as seen in the adult CASIZ 70066, which has resulted in a highly elongated prostate. The penial spines in CASIZ 309550 largely resemble the spines described by Bergh (1880, plate F, figs. 8–9) as well as the SEM micrographs of CASIZ 70066 (Dayrat 2010, fig. 202C); however, due to desiccation and perhaps the immature size of the individual the spines have not perfectly retained their conical shape and therefore do not exactly match the drawings and description in Bergh (1880) and Dayrat (2010). The bursa copulatrix studied here is large and rounded and more closely resembles the one found in Bergh (1880, plate F, fig. 5), than the bean-shaped one found in Dayrat (2010, fig. 200B). The accessory gland is similar in shape to the accessory gland for CASIZ 70066 (Dayrat 2010, fig. 200B) and for Bergh’s original drawings (Bergh 1880, plate F, fig. 5); however, the accessory spine studied here has a narrower base. In Bergh’s original drawings, the accessory spine has a broad base with a curved cusp and a narrow tip (Bergh 1880, plate F, figs. 12–14), as does the specimen CASIZ 70066 (Dayrat 2010, fig. 203B); while CASIZ 309550 is immature resulting in an under-developed accessory spine which has not achieved the expected length, breadth or curvature and more closely resembles the smaller specimen illustrated by Dayrat (2010, fig. 203D for CASIZ 109748 #3).
There is little doubt that the material studied here from Palau and Japan represent a single species. The morphological similarities and the molecular analyses confirm that the Japanese specimen (CASIZ 070066) is conspecific with the specimen from Palau (CASIZ 309550). The geographical distribution of H. desmoparypha is poorly understood within the Indo-Pacific, but specimens have been documented in Palau Bergh (1880) and Indonesia (Bergh 1905) with distribution from at least Palau to Japan confirmed here.
description: Published as part of Donohoo, Samantha A. & Gosliner, Terrence M., 2020, A tale of two genera: the revival of Hoplodoris (Nudibranchia: Discodorididae) with the description of new species of Hoplodoris and Asteronotus, pp. 1-37 in Zootaxa 4890 (1) on pages 14-16, DOI: 10.11646/zootaxa.4890.1.1, http://zenodo.org/record/4301483