Otinodoris

Valdés, Ángel, 2002, A phylogenetic analysis and systematic revision of the cryptobranch dorids (Mollusca, Nudibranchia, Anthobranchia), Zoological Journal of the Linnean Society 136 (4), pp. 535-636 : 604-607

OTINODORIS SP.

( FIGS 34B , 39-41 )

Type material

Off Hotel Soanambo , Île Saint Marie, Madagascar, 5 April 1990, 155 mm preserved length, leg. H. Chaney ( CASIZ 073238 ) .

External morphology

The background colour of the living animals is sandy yellow ( Fig. 34B ). The dorsum is covered with large, irregular brown and opaque white patches of different sizes and shapes. There is a black spot on top of the longest dorsal tubercles. The rhinophores are pale violet, with a number of irregular white spots. The branchial leaves are also pale violet with white rachises. The anal papilla is white. The whole dorsum is covered with a number of soft, elongate and ramified tubercles of various shapes and sizes ( Fig. 39D ). Some larger tubercles are randomly distributed among the others. The rhinophoral and branchial sheaths have papillae similar to those on the rest of the dorsum. There are six tripinnate branchial leaves. The anal papilla is situated in the centre of the branchial circle of leaves. The rhinophores are elongate, having 26 lamellae in a 155-mm preserved length specimen.

Ventrally the anterior border of the foot is grooved and notched ( Fig. 40F ). The oral tentacles are very large and flattened, with an irregular shape.

Anatomy

The posterior end of the glandular portion of the oral tube has six strong retractor muscles ( Fig. 40E ) which attach to the body wall. The oval, muscular buccal bulb has two large additional muscles attached; two long salivary glands connect with it at each side of the oesophageal junction. The buccal bulb is longer than the glandular portion of the oral tube. The labial cuticle is smooth. The radular formula is 41 ¥ 76.0. 76 in a 155-mm preserved length specimen. Rachidian teeth are absent. The inner lateral teeth are hamate and lack denticles ( Fig. 39A ). The teeth from the middle portion of the half-row are larger than those closer to the medial portion of the radula ( Fig. 39B ). The outermost teeth are smaller and also lack denticles ( Fig. 39C ). The oesophagus is long and connects directly to the stomach.

The ampulla is very long and folded ( Fig. 40C ). It branches into a short oviduct and the prostate. The oviduct enters the female gland mass near to its centre. The prostate is large and flattened ( Fig. 40B ). It has two different portions that are clearly distinguishable in colour and texture. The prostate connects with a long duct that expands into the ejaculatory portion of the deferent duct. The penis is armed with large hooks ( Fig. 41A ) and covered by a hard cuticle. The muscular deferent duct opens into a common atrium with the vagina. The vagina is very long and convoluted, internally covered with a cuticular lining ( Fig. 41B ). At its proximal end it joins the large and irregular bursa copulatrix. From the bursa copulatrix leads another duct connecting to the uterine duct and the seminal receptacle. The bursa copulatrix is about 10 times as large as the elongate seminal receptacle. The seminal receptacle is elongate and granular.

In the central nervous system ( Fig. 40D ) the cerebral and pleural ganglia are fused and distinct from the pedal ganglia. The cerebral and pleural ganglia are entirely covered with large ganglionic tubercles. There is one cerebral nerve leading from the left cerebral ganglion and two from the right one, and three pleural nerves leading from each pleural ganglion. There is no separate abdominal ganglion on the right side of the visceral loop. The buccal ganglia are near to the rest of the central nervous system, joined to the cerebral ganglia by two relatively long nerves. Gastrooesophageal, rhinophoral and optical ganglia are present. The pedal ganglia are clearly separated, having two nerves leading from each one. The pedal and parapedal commissures are enveloped together with the visceral loop.

The circulatory system ( Fig. 40A ) consists of a large heart and two blood glands situated in front of and behind the central nervous system.

Remarks

White’s (1948) original description of Otinodoris winckworthi includes very little information, but two features she described for this species (the presence of denticulate lateral teeth and auriculated oral tentacles), clearly distinguishes it from the species studied here, which has smooth teeth and lacks auriculated oral tentacles.

Otinodoris sp. clearly belongs to the genus Otinodoris by having flattened oral tentacles and the dorsum covered with long and ramified tubercles.

Figures

Figure 34. Living animals. A, Paradoris indecora, Southern Spain, photo by D. Moreno. B, Otinodoris sp. (CASIZ 073238), photo by T. M. Gosliner. C, Sebadoris nubilosa, Seychelles, photo by T. M. Gosliner. D, Conualevia marcusi, La Paz Bay, Baja California Sur.

Figure 39. Otinodoris sp. (CASIZ 073238), SEM images of the radula and dorsal tubercles. A, inner lateral teeth; scale bar = 75 Mm. B, mid-lateral teeth; scale bar = 75 Mm. C, outer lateral teeth; scale bar = 43 Mm. D, dorsal tubercles; scale bar = 350 Mm.

Figure 40. Otinodoris sp. (CASIZ 073238). A, general view of the anatomy; scale bar = 4 mm. B, reproductive system; scale bar = 5 mm. C, detail of several reproductive organs; scale bar = 5 mm. D, central nervous system; scale bar = 1 mm. E, lateral view of the buccal bulb; scale bar = 4 mm. F, ventral view of the mouth area; scale bar = 5 mm.

Figure 41. Otinodoris sp. (CASIZ 073238), SEM images of the penial hooks and vagina. A, penial hooks; scale bar = 500 Mm. B, vaginal cuticular lining; scale bar = 100 Mm.