Notobryon thompsoni, Pola & Camacho-García & Gosliner, 2012

Pola, Marta, Camacho-García, Yolanda E. & Gosliner, Terrence M., 2012, Molecular data illuminate cryptic nudibranch species: the evolution of the Scyllaeidae (Nudibranchia: Dendronotina) with a revision of Notobryon, Zoological Journal of the Linnean Society 165 (2), pp. 311-336 : 325-327

publication ID

https://doi.org/ 10.1111/j.1096-3642.2012.00816.x

persistent identifier

https://treatment.plazi.org/id/5F038794-FF87-0470-4ED0-FC7CFA9276F9

treatment provided by

Marcus

scientific name

Notobryon thompsoni
status

SP. NOV.

NOTOBRYON THOMPSONI SP. NOV. ( FIGS 5D View Figure 5 , 8 View Figure 8 , 9 View Figure 9 )

Notobryon wardi Thompson & Brown, 1981: 437 , figures 1–2, misidentification; Gosliner, 1987: 105, middle photo, misidentification; Zsilavecz, 2007: 67, 4 figs, misidentification.

Material examined: Type material: Holotype: CASIZ 176363 , South Africa, western Cape Province, west False Bay, Dale Brook , 34°7.50′S, 18°27.12′E, intertidal zone, one adult specimen 18 mm preserved, 7.i.2008, coll. T. M. Gosliner, A. Valdés, M. Pola, L. Witzel, B. Moore & C. Stout, digital photograph GoogleMaps . Paratypes: CASIZ 176362 , South Africa, western Cape Province, west False Bay, Dale Brook , 34°7.50′S, 18°27.12′E, intertidal zone, one adult specimen 20 mm preserved, dissected, 7.i.2008, coll GoogleMaps . T. M. Gosliner, A. Valdés, M. Pola, L. Witzel, B. Moore & C. Stout, digital photograph . CASIZ 176364 , South Africa, western Cape Province, west False Bay, Dale Brook , 34°7.50′S, 18°27.12′E, intertidal zone, one immature specimen 10 mm preserved, 7.i.2008, coll GoogleMaps . T. M. Gosliner, A. Valdés, M. Pola, L. Witzel, B. Moore & C. Stout, digital photograph . CASIZ 176277 , South Africa, Cape Province, Atlantic coast, Oudekraal, Mushroom Rock , 33°58.91′S, 18°21.61′E, 14 m maximum depth, one adult specimen 18 mm preserved, dissected, 5.i.2008, coll GoogleMaps . T. M. Gosliner, A. Valdés, M. Pola, L. Witzel, B. Moore & C. Stout, digital photograph . CASIZ 176925 , South Africa, Cape Province, Atlantic coast, Oudekraal, Oudekraal , 33°58.91′S, 18°21.61′E, 12 m maximum depth, one specimen 12 mm preserved, dissected, 13.i.2008, coll GoogleMaps . T. M. Gosliner, A. Valdés, M. Pola, L. Witzel, B. Moore & C. Stout, digital photograph . CASIZ 176956 , South Africa, Cape Province, Atlantic coast, Oudekraal, Coral Gardens , Hottentot’s Huisie , 33°59.29′S, 18°20.98′E, 17.5 m maximum depth, one immature specimen 12 mm preserved, dissected, 14.i.2008, coll GoogleMaps . T. M. Gosliner, A. Valdés, M. Pola, L. Witzel, B. Moore & C. Stout, digital photograph . CASIZ 073189 , South Africa, Cape Province, Atlantic coast, Oudekraal, Coral Gardens , Hottentot’s Huisie , north of Llandudno , one specimen 15 mm preserved, i.1981, coll . T. M. Gosliner . CASIZ 074100 , South Africa, Cape Province, False Bay, Dale Brook , 34°7.50′S, 18°27.12′E, one adult specimen 21 mm preserved, collection date unknown, coll GoogleMaps . T. M. Gosliner, digital photograph . CASIZ 073964 , South Africa, Cape Province, Atlantic coast, off Bloubergstrand , 4.6 m depth, one adult specimen 40 mm preserved, 14.ii.1980, coll. W . R. Liltved . SAM 33981 View Materials , South Africa, Cape Province, False Bay, Dale Brooks , intertidal, five immature specimens 3, 5, 8, 10, and 15 mm preserved, collection date unknown, coll . T. M. Gosliner . SAM CP614 View Materials B, South Africa, Cape Province, one adult specimen 20 mm preserved, dissected, 22.iii.1958, Ecological Survey, University of Cape Town . SAM KNY214 View Materials C, South Africa, Cape Province, one adult specimen 30 mm preserved, 7.vii.1960, ecological survey, University of Cape Town .

Geographical distribution: Currently known from South Africa ( Thompson & Brown, 1981; Gosliner, 1987; Debelius & Kuiter, 2007; Zsilavecz, 2007; present study), all specimens previously identified as N. wardi .

Etymology: Notobryon thompsoni is named after T. E. Thompson who was the first to describe this species based on several specimens that he collected in South

Africa ( Thompson & Brown, 1981), but he mistakenly identified this species as N. wardi .

External morphology ( Fig. 8 View Figure 8 ): The body is slender and laterally compressed. The front of the head is bilobed forming a thin oral veil. There is a distinctive posterior dorsal crest. The rhinophores are perfoliate with about ten to 15 lamellae. The rhinophoral sheaths have the characteristic elevated crest on its posterior face. There are two pairs of dorsolateral lobes. These lobes are markedly concave on the medial faces and the anterior pair is quite separate from the posterior pair leaving a large and straight space between the two of them. Both dorsolateral lobes are very similar in size, and more rounded rather than triangular, the first pair is sometimes slightly larger than the posterior pair. Each dorsolateral lobe bears four delicate secondary ‘gills’, although in one specimen ( CASIZ 074100) we counted up to six on the right side of the second pair of lobes. All the ‘gills’ are about the same size and very branched, looking like small trees. There is an extra secondary tripinnate ‘gill’ located just in front of the posterior end of the body. The anal papilla is located on the right side, immediately in front of the posterior lobe. The genital opening is on the right side, at a level behind and ventral to the right rhinophore. Minute holes or subcutaneous glands of unknown function cover the entire body.

The ground colour is pale brown or brown reddish with specks and some large blotchy areas of superficial blue-green pigment, often forming glistening apices on the pointed papillae of the flanks. There are also scattered dark brown spots over the sides and notum and dark brown pigment edges the dorsolateral lobes and the metapodial ridges. The medial faces of the spoon-like lobes show iridescent pink or green areas. The posterior crest of the rhinophoral sheaths, as well as their upper wavy margin, has the same iridescent pigment as the lobes. The tips of the rhinophores are iridescent green or blue. The lamellae are pale brown. The ‘gills’ are transparent but exhibit the same iridescent pigment that is present in the lobes, rhinophoral sheaths, and the posterior end.

Anatomy: The alimentary canal begins anteriorly with a buccal bulb that has a pair of elongate jaws ( Fig. 9A View Figure 9 ). The masticatory edge of the jaws is expanded into a wing-like flap. Over the edge of this flap is a series of polygonal rodlets that have a series of denticles along their outer edge. These rodlets form a honey-comb pattern over the entire surface of the masticatory edge ( Fig. 9B View Figure 9 ). The radula is broad and lacks rachidian teeth ( Fig. 9C View Figure 9 ). The radula formula is 12–19 ¥ 16–20.0.16–20. The specific formula for some of the specimens studied in this paper is shown in Table 1. Although it is difficult to see it seems that except for the inner and outermost teeth, each cusp bears denticles on both sides, always stronger on the outer face of each cusp ( Fig. 9D, E View Figure 9 ). The teeth gradually increase in size towards the outer margin except for the last two to three outer teeth that become smaller ( Fig. 9E View Figure 9 ). The salivary glands are elongate and flocculent surrounding the foremost part of the long and narrow oesophagus. We found eight conical gastric plates in the stomach ( Fig. 9F View Figure 9 ). The digestive gland forms three distinct unbranched lobes.

The reproductive system is shown in Figure 5D View Figure 5 . The ovotestis consists of two globular gonads lying on the upper side of the posterior digestive gland mass. From each gonad a thin-walled duct passes forwards to the hermaphroditic duct. The distal end of the hermaphroditic duct gets wider and expands into a long and convoluted ampulla that branches into the vas deferens and the oviduct. The oviduct enters the female gland mass. The vas deferens is short, wide, and somewhat folded. It lacks a morphologically welldifferentiated prostate gland mass but about half of its length has a different texture and appearance. The vas deferens ends in a digitiform, unarmed penis ( Fig. 9G, H View Figure 9 ). The vagina is short with an elongate bursa copulatrix.

Natural history: Found from the intertidal zone down to at least 15 m, but most commonly found intertidally. Feeds on hydroids. Prefers densely overgrown reefs ( Zsilavecz, 2007). This species, when disturbed, swims by lateral movements of the body.

T

Tavera, Department of Geology and Geophysics

R

Departamento de Geologia, Universidad de Chile

SAM

South African Museum

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Nudibranchia

Family

Scyllaeidae

Genus

Notobryon

Loc

Notobryon thompsoni

Pola, Marta, Camacho-García, Yolanda E. & Gosliner, Terrence M. 2012
2012
Loc

Notobryon wardi

Zsilavecz G 2007: 67
Gosliner TM 1987: 105
Thompson TE & Brown GH 1981: 437
1981