Amphorina linensis (Garcia-Gomez, Cervera & Garcia, 1990)

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/E075FF4A-6730-5246-9490-51546DE37E3E

treatment provided by

ZooKeys by Pensoft

scientific name

Amphorina linensis (Garcia-Gomez, Cervera & Garcia, 1990)
status

 

Amphorina linensis (Garcia-Gomez, Cervera & Garcia, 1990) View in CoL Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4d-e View Figure 4 , 7d View Figure 7

Eubranchus linensis Garcia-Gomez, Cervera & Garcia, 1990: 585-593.

Amphorina linensis (Garcia-Gomez, Cervera & Garcia, 1990): Martynov 1998: 775.

Eubranchus tricolor : sensu Trainito & Doneddu, 2014: 118, non Forbes, 1838.

Eubranchus sp. 1: Prkić et al., 2018: 353-357.

Material examined.

NE Atlantic, Skagerrak, Sweden, Västra Götalands län, Bohuslän, Väderöarna Islands (58°33'00"N, 11°02'30"E), 19 m depth, 09.04.2017, coll. Klas Malmberg, one specimen (GNM Gastropoda -9392, 10 mm in length, live, preserved length 4.2 mm). Mediterranean Sea, Croatia, Iž Island, Svežina (44°03'55"N, 15°07'15"E), 5 m depth, 13.01.2018, coll. A. Petani and Đani Iglić, two specimens (ZMMU Op-706, preserved length 6.5 mm, ZMMU Op-707, preserved length 6 mm).

Diagnosis.

Body up to 30 mm; dorsal spots, if present, reddish orange; in specimens with dorsal and ceratal spots distinct colouration of tail absent; completely pale specimens lack tail stripe or spot; light pinkish subapical ring on cerata absent; presence of distinct line of white pigment, sometimes punctuated, on the edge of the foot; cerata commonly broad with distinctly attenuated apices; digestive gland in cerata relatively thin without distinct short branches; up to six anterior rows of cerata; radular formula 38-61 × 1.1.1, copulative stylet relatively long, slightly bent at the middle, seminal receptacle elongate oval with moderate distinct stalk between reservoir and rapidly widened base.

Description.

External morphology. The length of adult specimens may reach 30 mm. The body is narrow. The rhinophores are smooth and 1.5-2 times longer than the oral tentacles. The cerata are relatively long, very broad, with distinctly attenuated apices. Ceratal formula of the specimen from Sweden (GNM 9392): right (2, 3, 3, 4; anus, 3, 2, 2, 1) left (2, 3, 4; anus, 3, 2, 2, 1). The foot is narrow, anteriorly without foot corners.

Colour. There are three main and eight subdivisions of colour variations (Fig. 3 View Figure 3 ), from completely pale body and cerata without pigment spots to specimens with very distinct reddish orange pigment spots on the body. In the specimens with distinct dorsal spots, there is never any pigmentation on the tail. A distinct white line is present on the external edge of the foot, although this could be broken or punctuated. No specimens found with blackish non-transparent pigmentation on the body, nor any homogeneously orange specimens. Absence of light pinkish subapical ring on cerata. Small white pigment dots of various density can be present on the cerata. The upper part of the rhinophores is commonly covered with white relatively dense dots with small insertions of yellowish brown pigment in some specimens, without the formation of ring-shaped colouration. The oral tentacles are similarly coloured.

Anatomy. Digestive system (Fig. 4 View Figure 4 , e3-e8). The jaws are triangularly ovoid. The masticatory processes of the jaws bear a single row of ca. 25 distinct denticles. The radular formula in the specimen studied from Croatia (Op-707) is 38 × 1.1.1. The radular teeth are yellowish. The central tooth is narrow, with a low cusp and four or five lateral denticles (three or less on anteriormost eroded teeth), including smaller intercalated denticles that may occur in different parts of the tooth.

Reproductive system. (Fig. 7D View Figure 7 ). The ampulla is relatively small, not distinctly swollen (Fig. 7D View Figure 7 , am). The prostate is distinct, relatively short and narrow (Fig. 7D 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. 4 View Figure 4 , e9, e10). A supplementary ( “penial”) gland is relatively long and inserts into the base of the penis (Fig. 7D View Figure 7 , pg). The seminal receptacle is elongate oval (Fig. 7D View Figure 7 , rs) with a distinct stalk between the reservoir and the widened base. The female gland mass includes mucous and capsular glands (Fig. 7D View Figure 7 , fgm).

Distribution and habitats.

Mediterranean Sea and all European Atlantic coasts to Sweden and Southwest Norway. At the Swedish west coast, living below the halocline.

Remarks.

Morphologically A. linensis differs from A. farrani , A. viriola sp. nov., A. andra sp. nov., and A. pallida by having reddish orange and not orange-yellow pigment spots (in spotted forms), the presence of a distinct, sometimes dotted white line along the foot edge, the shape of the cerata with attenuated apices, and a small ampulla. The present materials are well consistent with the original description of A. linensis (Garcia-Gomez et al. 1990) in such key characters as the shape of the cerata, the presence of a distinct white dotted line along the foot and reddish spots in some specimens, and the shape of the seminal receptaculum and prostate, but there are some differences in the number of rows of the radula, most likely due to specimen size differences. Adriatic specimens differ from the Atlantic ones in smaller size and different colouration. There is often a light blue pigmentation that covers cerata, rhinophores and oral tentacles, partially or completely, often the whole animal has a bluish appearance. No specimens with dorsal reddish dots have been found so far at the Adriatic coast. Mediterranean specimens of A. linensis have been frequently misidentified in the literature as Eubranchus tricolor .

Minimum uncorrected p-distances of the COI marker which separate the A. linensis from A. viriola sp. nov., A. andra sp. nov., A. farrani , and A. pallida are 9.15%, 11.42%, 10.05%, and 13.70% respectively.

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Nudibranchia

Family

Eubranchidae

Genus

Amphorina

Loc

Amphorina linensis (Garcia-Gomez, Cervera & Garcia, 1990)

Korshunova, Tatiana, Malmberg, Klas, Prkic, Jakov, Petani, Alen, Fletcher, Karin, Lundin, Kennet & Martynov, Alexander 2020
2020
Loc

Eubranchus tricolor

Forbes 1838
1838
Loc

Eubranchus

E.Forbes 1838
1838