Dermatobranchus caeruleomaculatus, Gosliner & Fahey, 2011

Gosliner, Terrence M. & Fahey, Shireen J., 2011, Previously undocumented diversity and abundance of cryptic species: a phylogenetic analysis of Indo-Pacific Arminidae Rafinesque, 1814 (Mollusca: Nudibranchia) with descriptions of 20 new species of Dermatobranchus, Zoological Journal of the Linnean Society 161 (2), pp. 245-356 : 291-294

publication ID	https://doi.org/ 10.1111/j.1096-3642.2010.00649.x
persistent identifier	https://treatment.plazi.org/id/761B2D60-4858-E260-0ADA-FEE3FEBE3EBE
treatment provided by	Valdenar
scientific name	Dermatobranchus caeruleomaculatus
status	sp. nov.

Treatment

DERMATOBRANCHUS CAERULEOMACULATUS View in CoL SP. NOV. ( FIGS 30E, F View Figure 30 , 35–37 View Figure 35 View Figure 36 View Figure 37 )

Dermatobranchus sp. 12 Gosliner, Behrens & Valdés, 2008: 312, bottom photos.

Type material: Holotype: CASIZ 174172 , Waterfall Bay , south side Tioman Island, east Malaysia, 15 m depth, collected 4.x.2007 by T. Gosliner & D. Behrens . Paratypes; CASIZ 174173 , two specimens, one dissected, Waterfall Bay , south side Tioman Island, east Malaysia, 15 m depth, collected 4.x.2007 by T. Gosliner & D. Behrens . CASIZ 178234 , one specimen sampled for DNA, Waterfall Bay , south side Tioman Island, east Malaysia, 15 m depth, collected 4.x.2007 by T. Gosliner & D. Behrens . CASIZ 177481 , one specimen, dissected, with subsample for DNA, Mainit Bubbles , Calumpan Peninsula , Batangas Bay, Luzon Philippines (13°41.325498′N, 120°53.8308′E), 10 m depth, collected 20.iii.2008 by Gosliner et al GoogleMaps . CASIZ 177482 , one specimen, sampled for DNA, Mainit Bubbles , Calumpan Peninsula , Batangas Bay, Luzon Philippines (13.6887583°N, 120.897180°E), 10 m depth, collected 20.iii.2008 by Gosliner et al GoogleMaps .

Geographical distribution: Known from Indonesia, eastern Malaysia, Philippines ( Gosliner et al., 2008), and Papua New Guinea ( Coleman, 2008)

Etymology: The specific name caeruleomaculatus is a noun in apposition and refers to the bright blue spots present on the oral veil and notal margins.

Natural history: This species was found feeding on the soft coral, Dendronephthya sp. , on sandy slopes in 10–15 m of water. In one specimen ( CASIZ 177481), the entire anterior end of the body cavity was full of sclerites of Dendronephthya sp. ( Fig. 36A View Figure 36 ). The acutely pointed sclerites had completely penetrated the digestive tract and were present throughout the inside of the body wall. The egg mass ( Fig. 30F View Figure 30 ) is a highly convoluted ribbon attached to the sand by a mucus thread. There is a single egg per egg capsule.

External morphology: The body shape of the living animal ( Fig. 30E View Figure 30 ) is elongate, but broad, slightly flattened, and narrows at the posterior end. The foot does not project beyond the distinct mantle margin. The dorsum has approximately 24 well-elevated, longitudinal ridges on either side of the midline that may further divide posteriorly. The oral veil is large and expansive with slightly pointed corners. The wellseparated, bulbous rhinophores are situated behind the oral veil. They have a series of longitudinal lamellae on the rounded club, which has a small rounded apex. The stalk does not narrow noticeably. Marginal sacs are readily visible along the mantle edge.

There are no hyponotal or branchial lamellae under the mantle margin. The genital opening is situated in the anterior quarter of the body. The anus is situated approximately half of the way to the posterior end of the body.

The ground colour of the dorsum is white with a series of brown spots arranged in longitudinal lines along the margin of the ridges. The oral veil and the margin of the notum have a series of blue spots, each with a black centre. There are also fine brown spots on the posterior end of the oral veil. There is a marginal yellow-orange band on both the notum and the oral veil. The rhinophore stalk is white with brown spots and the club is dark brown to black with opaque white pigment on the lamellae. The tip of the rhinophores is white.

Buccal armature: The jaws ( Figs 35A View Figure 35 , 36B View Figure 36 ) are short and thick. Along the inner edge of the jaws, the masticatory margin is slightly irregular and lacks any denticles ( Fig. 35B View Figure 35 ). The radula ( Figs 35C View Figure 35 , 36C View Figure 36 ) is short and wide with formulae of 33 ¥ 108.1.1.1.108 ( CASIZ 174173) and 33 ¥ 68.1.1.1. ( CASIZ 177481). The rachidian teeth ( Figs 35D View Figure 35 , 36D View Figure 36 ) are narrow and elongate with a long central cusp with a rounded tip. At the base of each rachidian tooth are four to five short denticles on either side of the cusp. The inner laterals have a narrow base with an elongate cusp. They may have four to five denticles on their outer side ( Fig. 36D View Figure 36 ), or may lack any basal denticles ( Fig. 35D View Figure 35 ). The middle lateral teeth ( Figs 35E View Figure 35 , 36E View Figure 36 ) and the outer lateral teeth ( Figs 35F View Figure 35 , 36F View Figure 36 ) are all evenly arched with an elongate cusp and all lack any denticles.

Reproductive system ( Fig. 37 View Figure 37 ): The ampulla is thick and simply curved. It bifurcates to the large female gland mass and the vas deferens. The majority of the female gland mass is composed of the mucous gland whereas the membrane and albumen glands are much smaller. The vas deferens is relatively wide and convoluted and widens further as it enters the short bulbous penial sheath. Within the penial sheath, the penis is wide and short and terminates in a somewhat acute apex. Adjacent to the penis is the narrow curved vagina, which terminates in a relatively large, pyriform bursa copulatrix.

Remarks: Dermatobranchus caeruleomaculatus is one of several large species with a broad body, smooth jaws, and a wide radula consisting of numerous teeth. These taxa include D. gonatophorus , D. ornatus , D. nigropunctatus , D. sagamianus , D. multidentatus , D. tongshanensis , D. multistriatus , D. leoni , and D. dendronephthyphagus . Of these taxa, D. caeruleomaculatus is the only species that has fine brown spotting and blue spots on the notal and oral veil margins. Of these taxa only D. caeruleomaculatus and D. dendronephthyphagus have a narrow rachidian tooth with an elongate, narrow cusp. Both of these species also Gosliner, no depth recorded. SAM A35760, one specimen, 10 mm preserved, Umgazana, Indian Ocean, South Africa, collected 28.x.1981 by T. Gosliner.

Geographical distribution: This species has been reported from only a single locality, Umgazana on the Indian Ocean coast of South Africa (Gosliner, 1987, present study).

Natural history: This species is found in the subtropical waters of the Indian Ocean coast of South Africa, from the lower intertidal zone, where it feeds upon the blue soft coral, Sansibia flava (May, 1899) .

Etymology: The specific name caesitius is an adjective, from the Latin word for ‘bluish’, referring to the colour of the dorsum.

have thin, elongate lateral teeth that lack denticles. In D. caeruleomaculatus ( Figs 35D View Figure 35 , 36D View Figure 36 ), the rachidian tooth has three to four basal denticles whereas denticles are entirely absent in D. dendronephthyphagus ( Fig. 43E View Figure 43 ). It is interesting to note that these two species with similarly shaped radular teeth have been observed feeding on soft corals of the genus Dendronephthya . The reproductive system of D. caeruleomaculatus ( Fig. 37 View Figure 37 ) differs from that of D. dendronephthyphagus ( Fig. 44 View Figure 44 ) in two significant regards. In D. caeruleomaculatus , the penial sac is bulbous and the vagina is thin throughout its length, whereas in D. dendronephthyphagus the penial sac is cylindrical and the vagina is wide basally and much narrower distally.