Hypselodoris skyleri, 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 : 47-49

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.5980696
persistent identifier	https://treatment.plazi.org/id/411BF606-FFCC-FF8D-FC67-FE48FAFB6E67
treatment provided by	Plazi
scientific name	Hypselodoris skyleri
status	sp. nov.

Treatment

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

(FIGS 2O, 13K, 27, 28)

LSID: urn:lsid:zoobank.org:act:8944E0DB-1780-41E4-B926-82328F762D68

Hypselodoris maculosa? Rudman, 2003 View in CoL .

Hypselodoris View in CoL sp. 5 Gosliner et al., 2008: 265, third photograph.

Hypselodoris View in CoL sp. 10 Gosliner et al., 2015: 259, middle right photograph.

Type material

Holotype: NMP 0 41284 (formerly CASIZ 182780 ), subsampled for molecular study, dissected, Sea Pen dive site, 13.68736°N, 120.83283°E, Tingloy, Batangas, Luzon, Philippines, 18 May 2010, T. Gosliner. GoogleMaps

Paratypes: CASIZ 177305 , one specimen, dissected, Sepok Wall , 13.68806°N, 120.82678°E, Tingloy, Batangas, Luzon, Philippines, 17 March 2008, T. Gosliner GoogleMaps . CASIZ 200649 , one specimen, Bonito (Culebra) Island, 13.62978°N, 120.94738°E, Tingloy, Batangas, Luzon, Philippines, 4 May 2014, T. Gosliner GoogleMaps . CASIZ 200552 , one specimen, off Binacas , 13.77931°N, 120.10959°E, Lubang Island, Mindoro Occidental, Philippines, 29 May 2014, T.Gosliner GoogleMaps . CASIZ 217258 , one specimen, south side Tubod , 9.0502°N, 123.5144°E, Siquijor Island, Philippines, 10 April 2016, T. Gosliner GoogleMaps . CASIZ 217424 , one specimen, Tambobo Bay , 9.1374°N, 123.1149°E, Siaton, Negros Oriental, Philippines, 5 April 2016, T. Gosliner GoogleMaps . CASIZ 120921 , one specimen, Munjor Pinnacle , Enewetak Atoll, Marshall Islands, 21 April 1983, S. Johnson . CASIZ 194004 , one specimen, under rock, K9 Pinnacle , Kwajalein Atoll, Marshall Islands, 22 July 2013, S. Johnson .

Type locality

Sea Pen, Tingloy, Maricaban Island, Batangas, Philippines.

Geographical distribution

Known from the Philippines, Indonesia and the Marshall Islands (present study).

Etymology

This species is named for author Rebecca Johnson’s son, Skyler (Sky) Rodgers. The beautiful bright white spots on the mantle of this species are reminiscent of bright stars in the sky on a clear night. Sky, thanks for your patience, kindness and thoughtfulness. May you always stay curious about the stars and our place in the universe.

Description

External morphology: Living animals ( Fig. 27 View Figure 27 A–D) small, reaching 15 mm in length. Body long, slender, translucent pink to peach. Fine parallel or intersecting brown longitudinal lines on notum sides of body and foot. Small, scattered opaque white spot situated on small tubercles on notum sides of body and foot. Scattered blue–purple spots found around margin of notum and foot; pigment more dense in centre of spot. Seven to eight unipinnate gill branches having a translucent white base and inner margin and bright red–orange pigment on outer surface of rachis and some gill filaments. Inner surface with opaque white. Bulb of perfoliate rhinophores opaque white with three red transverse bands and bearing about seven to ten densely arranged lamellae. Base of rhinophores translucent white.

Mantle glands: Subcutaneous mantle glands simple and rounded in shape ( Fig. 2O View Figure 2 ). Glands situated around entire margin of body in six specimens 4–8 mm preserved length. Anterior and posterior glands larger than lateral ones.

Buccal armature: Muscular portion of buccal mass about equal in length to oral tube. Chitinous labial cuticle found at anterior end of muscular portion of the buccal mass bearing numerous jaw rodlets ( Fig. 28A View Figure 28 ). Rodlets sharply angled, acutely pointed with one to three apices and posterior lateral extensions. Radular formula of paratype (CASIZ 177305) 53 × 38.0.38. Rachidian row of teeth absent ( Fig. 28B View Figure 28 ). Innermost lateral teeth having two or three large, triangular denticles on inner side of bifid primary cusp, with another two or three 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. 28C View Figure 28 ) all lacking inner denticles but having three or four sharply pointed, triangular outer denticles. Outermost teeth having a narrower base and somewhat shorter tooth shape, with five or six rounded to pointed outer denticles ( Fig. 28D View Figure 28 ).

Reproductive system: Reproductive organs fully mature in one specimen examined (CASIZ 177305; Fig. 13K View Figure 13 ). Ampulla thick, convoluted, narrowing 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 long, convoluted, muscular ejaculatory portion. Ejaculatory portion widening into much enlarged penial bulb. Penial papilla distinctly curved with broad base, devoid of penial hooks. Penial bulb adjacent to straight, slightly narrow, widening into penial sac. 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 long vagina widening proximally, leading to minute receptaculum seminis and larger spherical, thin-walled receptaculum seminis. Receptaculum situated near base of bursa. Moderately short, narrow uterine duct emerging from vagina close to base of bursa and female gland mass, near albumen gland.

Remarks

Hypselodoris skyleri is a member of a large clade that includes H. katherinae sp. nov., H. paradisa sp. nov., H. maritima, H. rudmani and H. bertschi . It is sister to H. katherinae and H. paradisa . The ABGD analysis indicates that H. skyleri is clearly distinct from H. katherinae and H. paradisa . A detailed comparison of these species is found in the remarks section of H. katherinae and H. paradisa . The colour pattern of H. skyleri is similar to that of H. maculosa and H. decorata but differs in having brown rather than opaque white lines. In H. skyleri , the opaque white spots are scattered over the surface of the body and elevated on small tubercles. In H. maculosa and H. decorata , the spots are found only on the margins of the body and are flush with the body surface. In both H. skyleri and H. decorata there are three rhinophoral red rings, whereas there are only two in H. maculosa .

Both H. decorata ( Fig. 2D View Figure 2 ) and H. maculosa ( Gosliner & Johnson, 1999: fig. 29D) have mantle glands only at the anterior and posterior ends of the body, whereas H. skyleri also has many lateral glands. The jaw rodlets of H. skyleri have one to three cusps, whereas H. decorata ( Fig. 10 View Figure 10 ) and H. maculosa ( Fig. 11 View Figure 11 ) possess a single cusp. The radulae of H. skyleri , H. maculosa and H. decorata all have a similar formula and teeth of a similar shape. One notable difference is that the cusps and adjacent denticles on the inner and middle lateral teeth are more elongate in H. skyleri than in H. maculosa and H. decorata . In H. skyleri , the penis is proportionately wider than in H. maculosa and H. decorata and possesses a distinct penial papilla.