Geitodoris, PLANATA

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 : 600-603

GEITODORIS PLANATA ( ALDER & HANCOCK 1846)

( FIGS 37 , 38 )

? Doris testudinaria Risso, 1818: 370–371 .

Doris planata Alder & Hancock, 1846: 292–293 .

Doris complanata Verrill, 1880: 399 .

Type material

The type material of Doris testudinaria Risso is untraceable ( Valdés & Héros, 1999). SYNTYPE of Doris planata: Cumbray Island, Scotland, one specimen, 11 mm preserved length, dried ( HMNC, no registration number). SYNTYPES of Doris complanata : R / V Fish Hawk, United States Fish Commercial Steamer, Sta. 872 (40∞02¢36¢-N, 70∞22¢58¢-W), 157 m depth, South of Martha’s Vineyard, Massachusetts, USA, 4 September 1880, five specimens, 15–37 mm preserved length ( YPM 10405).

Additional material

Off Martha’s Vineyard, Massachusetts, USA, 267 m depth, 1881, two specimens, 38–41 mm preserved length ( USNM 804925 ). R / V Iselin, Central Atlantic Benchmark Program , Sta. A 1 (39∞14¢42¢-N, 72∞47¢18¢- W), 91 m depth, Off New Jersey, USA, one specimen, 6 mm preserved length ( USNM 832719 ) .

External morphology

The colour of living animals from the North-Western Atlantic is unknown; preserved specimens are uniformly pale brown. The general colour of living animals from the North-Eastern Atlantic is reddishbrown ( Cervera et al., 1985; Ortea, 1990). There is a number of dark brown patches irregularly scattered on the dorsal surface. The patches situated near to the mantle margin are smaller than those on the centre of the dorsum. The rhinophores are pale cream with some brown and opaque white spots and the apices white. The gill is dark brown with the apices of the leaves opaque white. The whole dorsum is covered with small, rounded tubercles ( Fig. 37E ). There are a few larger tubercles surrounded by areas with smaller tubercles. The rhinophoral and branchial sheaths have tubercles no different from those on the rest of the dorsum. There are nine tripinnate branchial leaves arranged in an oval pattern. The rhinophores are elongate, having 27 lamellae in a 36-mm preserved length specimen.

Ventrally there are two short oral tentacles ( Fig. 38E ). 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. 38D ) 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 shorter than the glandular portion of the oral tube. The labial cuticle has two areas with a number of simple rodlets ( Fig. 37D ). The radular formula is 13 ¥ 20.0. 20 in a 27-mm preserved length specimen. Rachidian teeth are absent. The lateral teeth are narrow and elongate, having a single cusp and lacking denticles ( Fig. 37A ). The teeth from the middle portion of the half-row are larger than those closer to the medial portion of the radula ( Fig. 37B ). The cusp of the inner and midlateral teeth is very short compared to the base of the teeth. The 5–7 outermost teeth are elongated, lack a cusp and have a number of thin denticles on each side ( Fig. 37C ). The oesophagus is long and connects directly to the stomach.

The ampulla is long and curved ( Fig. 38C ). It branches into a short oviduct and the prostate. The oviduct enters the female gland mass near to its centre. The prostate is long and flattened and has two portions distinguishable by their colour and texture ( Fig. 38B ). It connects with a very long and convoluted duct that narrows and expands again into the large ejaculatory portion of the deferent duct. The muscular deferent duct opens into a common atrium with the vagina. From the atrium, near to the vaginal opening leads a muscular and elongate accessory gland. The vagina is long. 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 ( Fig. 38C ). The bursa copulatrix is oval in shape, about 10 times as large as the seminal receptacle.

In the central nervous system ( Fig. 38F ) the cerebral and pleural ganglia are fused and distinct from the pedal ganglia. There are three cerebral nerves leading from each cerebral ganglion and four 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 short nerves. Gastrooesophageal, rhinophoral and optical ganglia are present. The pedal ganglia are clearly separated, having three nerves leading from the left ganglion and four from the right one. The pedal and parapedal commissures are enveloped together with the visceral loop.

The circulatory system ( Fig. 38A ) consists of a large heart and two blood glands situated in front of and behind the central nervous system.

Remarks

Risso (1818) described Doris testudinaria from the Mediterranean coast of France. Later Risso (1826) illustrated this species, which has a dark body, brownish towards the mantle margin with yellowish lines that form small regular polyhedrons on the dorsum, and a reddish-orange underside.

Alder & Hancock (1846) described Doris planata from Scotland, as reddish brown, interspersed with dull lemon-yellow and purple-brown patches, the whole sprinkled with minute dark brown spots. A few irregular patches of dull yellow run down each side. Other distinctive features of this species are the dorsum covered with obtuse warty tubercles, mostly minute but of very unequal sizes, the anterior border of the foot grooved and notched and the seven branchial leaves small in size and strongly blotched with opaque yellowish white and dark brown. The colour of the foot was described as deep lemon.

Alder & Hancock (1862) redescribed Doris testudinaria as a different species from Doris planata , based on material from the British Isles. At the same time they recognized that Doris planata could be a juvenile form of Doris testudinaria . The only differences they found between these two species are the smaller branchial leaves, the more conspicuous dark brown markings and the presence of a central branchial leave in D. planata .

Years later Verrill (1880) described Doris complanata from Massachusetts, based on preserved specimens, pale brown to dusky brown, more or less mottled, back nearly smooth with few minute verrucae. Bergh (1894) studied one of Verrill’s original specimens and described the anatomy in full detail. No information on the colour of the living animals of this species is available.

Vayssière (1904) described Archidoris stellifera based on von Ihering’s manuscript notes and specimens he collected himself in the Mediterranean Sea. This species is characterized by having a reddishbrown or greyish-brown dorsum with darker spots and also several large, star-shaped, yellow patches arranged in three lines in the centre of the body. The underside is yellowish-orange. There are no jaws and the radular teeth are simple and hamate.

Eliot (1905a) suggested that Doris planata and Doris complanata are probably synonyms. The only differences he found between specimens from both sides of the Atlantic are the smaller size, smaller radula and smaller number of branchial leaves of the European specimens. Eliot (1905b) also suggested that the Mediterranean Doris testudinaria Risso, 1818 could be a synonym of Geitodoris planata . Only one year later Eliot (1906b) described a new species of Geitodoris from Cape Verde Islands, named Geitodoris reticulata Eliot, 1906 .

Thompson & Brown (1984) regarded Doris testudinaria and Archidoris stellifera as synonyms of Geitodoris planata (as Discodoris planata ). They did not provide detailed explanation for these synonymies but based their conclusions on Alder’s authority.

Cervera et al. (1985) and Ortea (1990) redescribed G. planata based on animals collected from southern Spain and the Canary Islands. According to these authors this species is reddish-brown with some dark spots in a dorsal-lateral position fading toward the cream edges. The dorsum also has several yellowish, star-shaped patches situated in two rows along the centre of the body. This coloration is also very similar to that described by Vayssière (1904) for Archidoris stellifera . Cervera et al. (1985) and Ortea (1990) considered that Archidoris stellifera is a different species from Geitodoris planata because of differences in the radular morphology. Perrone (1987) redescribed Archidoris stellifera from Italy (in the binomen Discodoris stellifera ) and confirmed the absence of jaws, the presence of hamate radular teeth and also described the existence of caryophyllidia. This evidence indicates that Archidoris stellifera should be placed in a genus of caryophyllidia-bearing dorids and is different from Geitodoris planata .

Examination of the type material of Geitodoris complanata and its comparison with anatomical studies on the European Geitodoris planata and the radula of the syntype of this species deposited at HMNC, confirms that these two names are synonyms. More problematic is the case of Doris testudinaria Risso, 1818 . The external characteristics of this species, described by Risso (1826) are similar to those of Geitodoris planata and Archidoris stellifera , and it is not possible to determine its identity at this point. Also, the type material of Doris testudinaria is untraceable.

Geitodoris reticulata , redescribed by Martínez et al. (1996) is clearly a distinct species. The reproductive system and the radula differ considerably from those of G. planata . There are several more species of Geitodoris described from the Mediterranean Sea and the Canary Islands.

Figures

Figure 37. Geitodoris planata (YPM 10405), SEM images of the radula, jaws and dorsal tubercles. A, inner lateral teeth; scale bar = 100 Mm. B, mid-lateral teeth; scale bar = 100 Mm. C, outer lateral teeth; scale bar = 75 Mm. D, jaw elements; scale bar = 30 Mm. E, dorsal tubercles; scale bar = 300 Mm.

Figure 38. Geitodoris planata (YPM 10405). A, general view of the anatomy; scale bar = 1 mm. B, reproductive system; scale bar = 0.5 mm. C, detail of several reproductive organs; scale bar = 0.5 mm. D, lateral view of the buccal bulb; scale bar = 1 mm. E, ventral view of the mouth area; scale bar = 1 mm. F, central nervous system; scale bar = 1 mm.