Peltodoris nobilis

PELTODORIS NOBILIS (MACFARLAND, 1905)

(FIGS 4I, 30, 31)

Montereina nobilis MacFarland, 1905: 38–39.

Type material

HOLOTYPE (by original designation): Monterey Bay, California, leg. F. M. MacFarland (USNM 181284), not examined.

Additional material

Pacific Grove, Monterey Bay, California, USA, July– August 1923 and May 1926, 10 specimens, 24–67 mm preserved length, leg. F. M. MacFarland (CASIZ 068237).

External morphology

The general colour of the living animals varies from whitish to orange-yellow (Fig. 4I). There is a number of dark brown or black small spots distributed on the entire dorsum below the level of the tubercles. The rhinophores have a light yellow base and a orange club. The gill is pale yellow with the apices of the leaves opaque white. The whole dorsum is covered with small, rounded tubercles (Fig. 30D). The largest tubercles are situated in the central region of the body. The rhinophoral and branchial sheaths have tubercles no different from those on the rest of the dorsum. There are five tripinnate branchial leaves, forming a circle. The anal papilla is situated in the centre of the branchial circle of leaves. The rhinophores are elongate, having 17 lamellae in a 54-mm preserved length specimen.

Ventrally there are two long and conical oral tentacles (Fig. 31E). The anterior border of the foot is grooved and notched.

Anatomy

The posterior end of the glandular portion of the oral tube has six strong retractor muscles (Fig. 31D) which attach to the body wall. The oval, muscular buccal bulb has two additional muscles attached; two long and wide salivary glands connect with it at each side of the oesophageal junction. The buccal bulb is twice the length of the glandular portion of the oral tube. The labial cuticle is smooth. The radular formula is 27 ¥ 57.0. 57 in a 54-mm long specimen. Rachidian teeth are absent. The lateral teeth are narrow and elongate, having a single cusp and lacking denticles (Fig. 30A). The teeth from the middle portion of the half-row are larger than those closer to the medial portion of the radula (Fig. 30B). The outermost teeth are smaller and also lack denticles (Fig. 30C). The oesophagus is short and connects directly to the stomach (Fig. 31A).

The ampulla is very long and convoluted (Fig. 31C). It branches into a short oviduct and the prostate. The oviduct enters the female gland mass near to its centre. The prostate is flattened and has two portions distinguishable by their colour and texture (Fig. 31B). It connects with a long duct that narrows and expands again into the large ejaculatory portion of the deferent duct. The muscular deferent duct opens into a short common atrium with the vagina. The vagina is long and convoluted. At its proximal end it joins the bursa copulatrix. From the bursa copulatrix leads another duct connecting to the uterine duct and the seminal receptacle. The bursa copulatrix is oval in shape, about eight times as large as the seminal receptacle (Fig. 31B).

In the central nervous system (Fig. 31D) the cerebral and pleural ganglia are fused and distinct from the pedal ganglia. There are three cerebral nerves leading from each cerebral ganglion and two pleural nerves leading from each pleural ganglion. There is a 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 short nerves. Gastrooesophageal, rhinophoral and optical ganglia are present. The pedal ganglia are clearly separated, having four nerves each one. The pedal and parapedal commissures are enveloped together with the visceral loop.

The circulatory system (Fig. 31A) consists of a large heart and a two blood glands situated in front of and behind the central nervous system.

Remarks

Peltodoris nobilis is a well-known species from the Pacific Coast of North America (see McDonald, 1983). It was originally described in the genus Montereina (MacFarland, 1905) and later transferred to the genus Anisodoris.