Hypselodoris alburtuqali, Gosliner & Johnson, 2018

Epstein, Hannah E., Hallas, Joshua M., Johnson, Rebecca Fay, Lopez, Alessandra & Gosliner, Terrence M., 2018, Reading between the lines: revealing cryptic species diversity and colour patterns in Hypselodoris nudibranchs (Mollusca: Heterobranchia: Chromodorididae), Zoological Journal of the Linnean Society 20 (1), pp. 1-74 : 7-12

publication ID	https://doi.org/ 10.1093/zoolinnean/zly048
publication LSID	urn:lsid:zoobank.org:pub:F0065FD2-417C
DOI	https://doi.org/10.5281/zenodo.5980666
persistent identifier	https://treatment.plazi.org/id/411BF606-FFE4-FFB6-FEB8-FA1CFA326F3A
treatment provided by	Plazi
scientific name	Hypselodoris alburtuqali
status	sp. nov.

Treatment

HYPSELODORIS ALBURTUQALI GOSLINER & JOHNSON View in CoL SP. NOV.

(FIGS 1A, 2A, 3, 4A)

LSID: urn:lsid:zoobank.org:act:5597044A-A9B3-4A7F-8FBF-25A512DB71CF

Hypselodoris View in CoL sp. 2 Gosliner et al., 2015: 254, bottom left photograph.

Type material

Holotype: CASIZ 192295 , subsampled for molecular study, dissected, Abulad Island , Farasan Islands, Red Sea, Saudi Arabia, 8 m depth, 10 March 2013, T. M. Gosliner.

Type locality

Abulad Island, Farasan Islands, Saudi Arabia, Red Sea.

Geographical distribution

Saudi Arabian Red Sea.

Etymology

Hypselodoris alburtuqali is named for the Arabic word for ‘the orange one’, al burtuqali, owing to the orange coloration of this species.

Description

External morphology: Living animals ( Fig. 1A View Figure 1 ) moderately large, reaching 30 mm in length. Body translucent pink, with about eight continuous or interrupted longitudinal lines on dorsal surface of notum. Anterior and posterior ends of the animal more opaque white than pink. Additional opaque white lines located on sides of animal and on posterior portion of foot. Longitudinal rows of dark brown spots situated between opaque white lines of notum and foot. Wide red–orange marginal band present along entire mantle and foot margins. Eight unipinnate gill branches having a translucent white base and bright red–orange pigment on apical surfaces and outer margin. Bulb of perfoliate rhinophores opaque white with two red–orange transverse bands and bearing about ten densely arranged lamellae. Base of rhinophores translucent white.

Mantle glands: Subcutaneous mantle glands simple and rounded in shape ( Fig. 2A View Figure 2 ). Glands situated anteriorly and posteriorly, with no glands present in the central lateral regions of body margin. Nine to ten glands on either side of anterior end of the body, with arc of nine glands situated posteriorly.

Buccal armature: Muscular portion of buccal mass about twice length of oral tube. Chitinous labial cuticle found at anterior end of muscular portion of the buccal mass ( Fig. 3A View Figure 3 ) bearing numerous jaw rodlets ( Fig. 3B View Figure 3 ). Rodlets narrowly ovoid, with single, acutely pointed apex. Radular formula of holotype 44 × 26.0.26 ( Fig. 3C View Figure 3 ). Rachidian row of teeth absent ( Fig. 3D View Figure 3 ). Innermost lateral teeth having one or two large, triangular denticles on inner side of bifid primary cusp, with another one to two outer denticles. Next several laterals lacking inner triangular denticle but possessing two or three denticles on outer side of primary bifid cusps. Midlateral teeth ( Fig. 3E View Figure 3 ) all lacking inner denticles but having three or four sharply pointed, triangular outer denticles. Outermost teeth having a narrower base and shorter tooth shape, with three or four rounded outer denticles ( Fig. 3F View Figure 3 ), often larger than bifid cusps.

Reproductive system: Reproductive organs of the holotype fully mature ( Fig. 4A View Figure 4 ). Ampulla thick, tubular, narrowing

G, Hypselodoris juniperae Gosliner & Johnson sp. nov., CASIZ 177550. H, Hypselodoris katherinae Gosliner & Johnson sp. nov., CASIZ 177532 . I, Hypselodoris krakatoa Gosliner & Johnson, 1999 , CASIZ 206801 . J, Hypselodoris lacuna Gosliner & Johnson sp. nov., paratype, CASIZ 208652 . K, Hypselodoris paradisa Gosliner & Johnson sp. nov., holotype, CASIZ 191464 . L, Hypselodoris perii Gosliner & Johnson sp. nov., NMP 0 41281. M, Hypselodoris roo Gosliner & Johnson sp. nov., paratype, CASIZ 204801 . N, Hypselodoris rositoi Gosliner & Johnson sp. nov., holotype, NMP 0 41283. O, Hypselodoris skyleri Gosliner & Johnson sp. nov., composite of five specimens ( CASIZ 200649 , CASIZ 177305 , NMP 0 41284, CASIZ 200552 and CASIZ 217424 ) .

somewhat before bifurcating into oviduct and vas deferens. Short oviduct entering female gland mass near albumen gland. Prostatic proximal portion of vas deferens convoluted, curved and thick and narrowing slightly as it transitions into muscular, ejaculatory portion. Ejaculatory portion widening again before entry into wider penial bulb. Penial bulb adjacent to straight, very wide vaginal duct at common gonopore. Distal end of vas deferens devoid of penial hooks. Female gland mass consisting of large mucous gland and small membrane and albumen glands. Large, lobate vestibular gland situated near exit of mucous gland. Relatively short vagina leading to minute receptaculum seminis and larger spherical, thinwalled receptaculum seminis. Moderately long uterine duct emerging from vagina close to base of bursa and female gland mass, near albumen gland.

Remarks

The colour pattern of H. alburtuqali most closely resembles that of Goniobranchus sp. 29 ( Gosliner et al., 2015: 227 upper left photograph), with which it is sympatric. Our molecular phylogeny ( Fig. 35 View Figure 35 ) clearly indicates that this species is in the H. maculosa clade. It is sister to the clade that includes H. decorata ( Risbec, 1928) , H. juniperae sp. nov., H. maculosa ( Pease, 1871) and H.yarae sp. nov. and is shown to represent a distinct species in our ABGD analysis. The colour pattern most closely resembles that of H. decorata and H. yarae , but H. alburtuqali has a narrower red–orange margin, more longitudinal opaque white lines and more, smaller brown spots compared with H. decorata and H. yarae . Additionally, H. decorata has opaque white spots and purple markings on its anterior and posterior margins of the notum that are absent in H. alburtuqali and H. yarae . All of the members of this clade, including those species that were studied by Gosliner & Johnson (1999) and are not included in the present molecular phylogeny, have distinctive colour patterns on their rhinophores. Hypselodoris alburtuqali , H. maculosa , H. peasei, Hypselodoris insulana Gosliner & Johnson, 1999 , Hypselodoris alboterminata Gosliner & Johnson, 1999 and H. juniperae have two reddish rhinophoral rings. In contrast, the rhinophores of Hypselodoris violabranchia Gosliner & Johnson, 1999 have a reddish base and a violet apex. The rhinophores of H. decorata and H. yarae have three red rhinophoral rings, and those of Hypselodoris maridadilus Rudman, 1977 , H. whitei ( Adams & Reeve, 1850) and H. emma all have uniformly red rhinophores with a white apex. Of those species with two red rhinophoral rings, H. insulana and H. peasei lack dark brownish spots on the notum and have more numerous opaque white lines on the notum, and H. juniperae has purple rather than dark brown spots and opaque white spots rather than lines on the notum.

Hypselodoris alburtuqali has mantle glands that are distributed completely around the anterior and posterior margins of the mantle, with no glands present along most of the lateral notal margins. Of the other members of this clade, only H. maculosa , H. decorata , H. juniperae , H. alboterminata and H. whitei have this arrangement of mantle glands ( Gosliner & Johnson, 1999; present study, Fig. 2 View Figure 2 ). Hypselodoris peasei, H. insulana , H. violabranchia and H. emma have a similar arrangement of mantle glands, but lack glands along the anterior edge and have anterior glands only along the anterolateral margins ( Gosliner & Johnson, 1999). In H. maridadilus , the mantle glands are distributed along the entire margin of the mantle with the exception of the anterior margin, which is devoid of glands, whereas in H. yarae , the mantle glands are present all around the mantle margin.

The radulae of most members of this clade are very similar in the shape of their teeth and in the number of denticles on the teeth. Hypselodoris alburtuqali has three or four denticles on the middle lateral teeth, as do H. alboterminata , H. decorata , H. insulana , H. yarae and H. juniperae . In H. emma and H. maculosa there are four or five denticles, and H. violacea has five or six denticles ( Gosliner & Johnson, 1999; present study).

The reproductive system of H. alburtuqali is unique among members of the H. maculosa clade in having a much wider vagina ( Fig. 4A View Figure 4 ). In H. maculosa ( Fig. 4B View Figure 4 ) H. decorata ( Fig. 4H View Figure 4 ) and H. yarae ( Fig. 33B View Figure 33 ), the vagina is much narrower. In H. alburtuqali , H. decorata and H. maculosa , the receptaculum seminis is situated at the base of the bursa copulatrix or immediately below it, whereas in H. yarae it is much more distally situated. In H. alburtuqali , the uterine duct connects to the vagina immediately below the bursa and receptaculum, whereas in H. decorata and H. maculosa the uterine duct branches from the vagina well below the base of the bursa and receptaculum. In H. yarae , the uterine duct emerges from the base of the vagina, near the genital opening, and has an expanded base adjacent to its juncture with the vagina.