Amphorina andra, Korshunova & Malmberg & Prkić & Petani & Fletcher & Lundin & Martynov, 2020

Korshunova, Tatiana, Malmberg, Klas, Prkic, Jakov, Petani, Alen, Fletcher, Karin, Lundin, Kennet & Martynov, Alexander, 2020, Fine-scale species delimitation: speciation in process and periodic patterns in nudibranch diversity, ZooKeys 917, pp. 15-50 : 15

publication ID	https://dx.doi.org/10.3897/zookeys.917.47444
publication LSID	lsid:zoobank.org:pub:75B05B61-9395-44E9-95BC-AE945C2D3B83
persistent identifier	https://treatment.plazi.org/id/91211302-2EFC-4BC5-913E-1DE47D8DE2FA
taxon LSID	lsid:zoobank.org:act:91211302-2EFC-4BC5-913E-1DE47D8DE2FA
treatment provided by	ZooKeys by Pensoft
scientific name	Amphorina andra
status	sp. nov.

Treatment

Amphorina andra sp. nov. Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 6 View Figure 6 , 7c View Figure 7

Eubranchus farrani : sensu Schmekel and Portmann 1982: 241-243, taf. 14, Fig. 1 View Figure 1 - 3 View Figure 3 , abb. 7.78 (= Amphorina andra sp. nov. + mixture of species).

Eubranchus farrani : sensu Trainito & Doneddu, 2014: 117 (four lower figs), non Alder & Hancock, 1844.

Eubranchus farrani : sensu Prkić et al. 2018: 347, figs 3a-b; p. 348, figs 1a-e; p. 349, figs 1a-d; 350, figs 1a-d; 351, figs 1a-d, non Alder & Hancock, 1844.

Material examined.

Holotype. NE Atlantic, Skagerrak, Sweden Region Västra Götaland, Bohuslän county, town of Smögen, outermost skerries (58°22'00"N 11°11'00"E), 15-20 m depth, 29.04.2018, coll. Klas Malmberg (GNM Gastropoda - 9717, ca. 12 mm in length, live, preserved length ca. 5 mm).

Paratypes.

NE Atlantic, Loch Fyne, Scotland, Great Britain (55°57'00"N, 05°23'00"W), 5-20 m depth, 24.05.2015, coll. Jim Anderson, one specimen (GNM Gastropoda -9266, preserved length 4 mm). NE Atlantic, Newlyn Marina, Cornwall, Great Britain (50°06'10"N, 05°32'45"W), 0-5 m depth, 12.08.2015, coll. David Fenwick, one specimen (GNM Gastropoda -9272, preserved length 3.5 mm). Mediterranean, Lecce, Italy (40°25'00"N, 18°16'00"E), 10-20 m depth, 20.02.2015, coll. Fabio Vitale, one specimen (GNM Gastropoda -9292, preserved length 2 mm). Mediterranean, Lecce, Italy (40°25'00"N, 18°16'00"E), 10-20 m depth, 05.08.2016, coll. Fabio Vitale, one specimen (GNM Gastropoda -9293, preserved length 2 mm). NE Atlantic, Skagerrak, Sweden, Region Västra Götaland, Bohuslän county, town of Smögen, outermost skerries (58°22'00"N, 11°11'00"E), 26 m depth, 29.04.2018, coll. Klas Malmberg (GNM Gastropoda - 9716, 12 mm in length, live, preserved length 10 mm). NE Atlantic, Skagerrak, Sweden, Region Västra Götaland, Bohuslän county, town of Smögen, Kleven, Smögen Dyk och Upplevelse Dive centre (58°16'00"N, 11°26'00"E), 15-20 m depth, 00.00.2018, coll. Klas Malmberg (GNM Gastropoda - 9720, 11 mm in length, live, preserved length 9 mm). Mediterranean Sea, Croatia, Split, Kašuni (43°50'55"N, 16°37'44"E), 20 m depth, 28.01.2018, coll. J. Prkić and Marko Lete, one specimen (ZMMU Op-703, ca. 11 mm in length, live, preserved length 6 mm).

Diagnosis.

Body up to at least 20 mm; large dorsal pigment spots, if present, bright yellow-orange or reddish orange; in specimens with yellow-orange or reddish spots on dorsal side and cerata, there is never any yellow-orange spot or stripe on the tail, but there could be a whitish median line on the tail; completely pale specimens lack tail stripe or spot; light pinkish subapical ring on cerata absent; absence of a punctuated white line or row of dots on the edge of foot; cerata commonly moderate in width without distinctly attenuated apices; digestive gland in cerata relatively broad without distinct short branches; up to four anterior rows of cerata; radular formula 30-37 x 1.1.1, copulative stylet very short, conical, seminal receptacle subcircular with long distinct stalk between reservoir and rapidly widened base.

Etymology.

" andra " from Swedish meaning "the other" referring to the separation from A. viriola .

Description.

External morphology. The live length of holotype is ca. 12 mm (Fig. 6a View Figure 6 ). The length of adult specimens may reach 20 mm. The body is narrow. The rhinophores are smooth and 1.5-2 times longer than the oral tentacles. The cerata are relatively long, swollen. Ceratal formula of the holotype: right (2; 3; 3; anus, 2, 3, 2, 2) left (2, 3, 3; anus, 3, 2, 2, 1). The foot is narrow, anteriorly without foot corners.

Colour. There are three main and several subdivisions of colour variations (Fig. 3 View Figure 3 ), from a completely pale body and cerata without orange-yellow pigment spots to specimens with dull orange-yellow spots on the body. In specimens with distinct dorsal spots, there is never any orange-yellow colouration on the tail, but there could be a whitish median line on the tail. The dorsal side of body can on some specimens be partially to almost completely covered with greyish-brown, dark brown or blackish pigment spots or blotches, similar colours can be present also on the cerata. Yet other specimens can be without any blackish surface pigmentation but with a uniformly homogeneous bright orange to golden yellow colour of the body (Fig. 3 View Figure 3 ). The tips of the cerata can be covered with orange-yellow pigment, or lack pigmentation, in which case the cnidosac is visible. There is always an absence of a light pinkish subapical ring, or any small subapical pinkish dots on the cerata. There is no distinct punctuated white line on the edge of the foot. The upper part of the rhinophores is commonly covered with orange to yellowish brown pigment and dispersed small white spots, without the formation of a pinkish pigment ring; occasionally the entire surface of the rhinophores is covered with yellowish orange or brownish pigment. The oral tentacles are similarly coloured.

Anatomy. Digestive system (Fig. 6 View Figure 6 , a4-a10, b4-b8, c4-c10. The jaws are triangularly ovoid. The masticatory processes of the jaws bear a single row of ca. 19-28 distinct denticles. The radular formula in four studied specimens is 30-37 x 1.1.1. The radular teeth are yellowish. The central tooth is narrow, with a low cusp and 3-5 lateral denticles, including smaller intercalated denticles that may occur in different parts of the tooth.

Reproductive system. (Fig. 7C View Figure 7 ). The ampulla is large and conspicuously swollen (Fig. 7C View Figure 7 , am). The prostate is distinct, relatively short and wide (Fig. 7C View Figure 7 , pr). The prostate transitions to a penial sheath, which contains a conical penis with a chitinous, very short, broadly conical stylet (Fig. 6 View Figure 6 , a9, a10). A supplementary ( “penial”) gland is relatively short and inserts into the base of the penis (Fig. 7C View Figure 7 , pg). The seminal receptacle is large, subcircular (Fig. 7C View Figure 7 , rs) with a large, widened base to which it transitions with a distinct long stalk. The female gland mass includes mucous and capsular glands (Fig. 7C View Figure 7 , fgm).

Distribution and habitats.

Mediterranean Sea and all European Atlantic coasts to Gulen at the mouth of Hardanger fjord, Norway, also possibly further north to the Trondheim fjord (Klas Malmberg, personal observation). Salinity-range: 33 to 35 ‰, ordinary oceanic salinity, or close to it. At the Swedish west coast, living below the halocline. In areas without halocline and more oceanic environments, it can be found closer to the surface or intertidally. In Croatia is quite common from very shallow water (0-0.5 m) to ca. 20 m.

Remarks.

Morphologically this inhabitant of waters with normal to nearly normal ocean salinity A. andra sp. nov. differs from the closely related strict inhabitant of brackish waters A. viriola sp. nov. a by the absence of light pinkish subapical rings on the cerata, the presence of forms with non-transparent blackish colouration or uniform orange colouration (Fig. 3 View Figure 3 ), a lower range of the number of lateral denticles on central radular teeth, a considerably larger, strongly swollen ampulla and subcircular instead of pear-shaped receptaculum seminis. From A. farrani , A. andra sp. nov. differs by the absence of orange-yellow colouration in spotted forms (see Discussion), and the presence of forms with blackish surface pigmentation on the body and cerata (Fig. 3 View Figure 3 ). Amphorina andra sp. nov. differs from A. linensis by the absence of a distinct dotted white line along edge of the foot, the smaller number of ceratal rows and shape of the cerata, the shape and size of the ampulla and receptaculum seminis. From A. pallida , A. andra sp. nov. differs by the larger size of the dorsal spots (in spotted forms), and the smaller number of anterior ceratal rows, the shape and size of the ampulla and receptaculum seminis.

Minimum uncorrected p-distances of the COI marker which separate the A. andra sp. nov. from A. farrani , A. viriola sp. nov., A. linensis , and A. pallida are 9.59 %, 0.15 %, 11.42 %, and 14.92 respectively.