Hypselodoris roo, 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 : 42-44

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.5980692
persistent identifier	https://treatment.plazi.org/id/411BF606-FFCB-FF96-FC97-FD48FA846EC3
treatment provided by	Plazi
scientific name	Hypselodoris roo
status	sp. nov.

Treatment

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

(FIGS 2M, 13I, 18H–J, 24)

LSID: urn:lsid:zoobank.org:act:2AEED331-248A-49A9-AC93-C0A38921233E

Hypselodoris kanga View in CoL misidentification, not H. kanga Rudman, 1977 View in CoL ; Krampf, 2007.

Hypselodoris kanga View in CoL misidentification, not H. kanga Rudman, 1977 View in CoL ; Debelius & Kuiter, 2007: 127, lower left photograph.

Hypselodoris View in CoL sp. 7 Gosliner et al., 2015: 258, upper right photograph.

Type material

Holotype: NMP 0 41282 (formerly CASIZ 181272 ), subsampled for molecular study, dissected, Mainit Bubbles , 13.6880278°N, 120.95809°E, Calumpan Pe n i n s u l a, M a b i n i, B a t a n g a s, L u z o n I s l a n d, Philippines, 21 May 2009, T. Gosliner. GoogleMaps

Paratypes: CASIZ 186098 , one specimen, Mainit Bubbles , 13.6880278°N, 120.8971833°E, Calumpan Pe n i n s u l a, M a b i n i, B a t a n g a s, L u z o n I s l a n d, Philippines, 4 May 2011, T. Gosliner GoogleMaps . CASIZ 204801 , one specimen, Giant Clam dive site, 13.51356°N, 120.95809°E, Puerto Galera, Mindoro Oriental, Philippines, 19 April 2015, T. Gosliner GoogleMaps . CASIZ 2 0 8 5 4 1, o n e s p e c i m e n, G i a n t C l a m d i v e s i t e, 13.51356°N, 120.95809°E, Puerto Galera , Mindoro Oriental, Philippines, 28 March 2015, T. Gosliner GoogleMaps . CASIZ 208193 , one specimen, Giant Clam dive site, 13.51356°N, 120.95809°E, Puerto Galera, Mindoro Oriental, Philippines, 25 March 2015, T. Gosliner GoogleMaps . CASIZ 217236 , one specimen, Murals dive site, 1 3.6 9 9 3°N, 1 2 0.8 8 2 4°E, C a l u m p a n Pe n i n s u l a, Mabini, Batangas, Luzon Island, Philippines, 22 April 2016, T. Gosliner . CASIZ 217308 , Pyramid dive site, 9.1721°N, 123.2519°E Dauin, Negros Oriental, Philippines, 7 April 2016, T. Gosliner GoogleMaps .

Type locality

Mainit Bubbles, Mabini, Batangas, Philippines.

Geographical distribution

Known from Indonesia and the Philippines ( Debelius & Kuiter, 2007; present study).

Etymology

Hypselodoris roo comes from the A. A. Milne character Roo, the kangaroo whose mother is Kanga. This species is named H. roo , because it has often been mistaken for H. kanga .

Description

External morphology: Living animals ( Fig. 18 View Figure 18 H–J) moderately large, reaching 45 mm in length. Body colour whitish to grey–blue. Sides of body high, with narrow mantle margin tapering posteriorly into rounded lobe. Notum ornamented with small to large yellow spots and smaller dark blue to black spots scattered over the surface.Areas of blue are present on the notum and sides of body. Additional spots of same colour found on sides of body and foot. Gill pocket slightly elevated from notum. Nine to eleven narrow, thin, unipinnate gill branches held erectly from gill pocket. Gill branches with red lines along edges of inner and outer surface. Apex of gill branch red–orange. Central portion of middle of outer face of gill branches with several opaque white spots. Base of rhinophores red, with opaque white spot on posterior face. Upper half of rhinophore club bright red. Rhinophores with 13–14 small lamellae.

Mantle glands: Subcutaneous mantle glands variable in distribution ( Fig. 2M View Figure 2 ). Posterior glands always present; lateral glands always absent; anterior glands present or absent. This arrangement was based on seven specimens examined, four of which had both anterior and posterior mantle glands and three that lacked anterior glands.

Buccal armature: Muscular portion of buccal mass somewhat larger than length of oral tube. Chitinous labial cuticle found at anterior end of muscular portion of the buccal mass bearing numerous jaw rodlets ( Fig. 24A View Figure 24 ). Rodlets narrow with short base and evenly curved, with single, acutely pointed apex. Radula broad, nearly as wide as long. Radular formula of holotype (CASIZ 191070) 71 × 79.0.79. Rachidian row of teeth absent ( Fig. 24B View Figure 24 ). Innermost lateral teeth having irregular triangular denticle on inner side of bifid primary cusp. Denticles absent from outer side of tooth. Next several laterals and middle lateral teeth ( Fig. 24C View Figure 24 ) with bifid cusp, lacking inner or outer denticles. Two outermost teeth having a narrower base and shorter tooth shape, with one or two rounded outer denticles ( Fig. 24D View Figure 24 ), smaller than bifid cusps.

Reproductive system: Reproductive organs of the holotype fully mature ( Fig. 13I View Figure 13 ). Ampulla thick, short, tubular and curved, narrowing somewhat before bifurcating into oviduct and vas deferens. Short oviduct entering female gland mass near albumen gland. Proximal prostatic portion of vas deferens relatively long, convoluted, curved and thick and narrowing slightly as it transitions into muscular ejaculatory portion. Ejaculatory portion relatively long, convoluted and narrow, entering elongate, wider penial bulb. Penial bulb adjacent to straight, 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 moderately long vagina leading to small, straight receptaculum seminis and larger spherical, thin-walled receptaculum seminis. Receptaculum seminis curving upwards towards base of bursa. Moderately long uterine duct emerging from vagina immediately below receptaculum, entering female gland mass, near albumen gland.

Remarks

Hypselodoris roo , together with H. confetti , has often been misidentified as H. kanga ( Rudman, 1999b; Debelius & Kuiter, 2007). These two species also have some external similarity to H. infucata . A detailed comparison of H. confetti and H. kanga is found above in the remarks for H. confetti . In our phylogenetic analysis, H. roo is sister to H. zephyra Gosliner & Johnson, 1999 and both are sister to H. confetti . In contrast, H. infucata is a well-separated clade and is sister to H. obscura.

Hypselodoris zephyra has intersecting blue lines on the notum, whereas H. roo has bluish pigment, but the blue never forms lines. Hypselodoris roo also has yellow spots, compared with the irregular yellow pustules found in H. zephyra . Hypselodoris roo has black spots, which are absent in H. zephyra . Hypselodoris zephyra lacks the opaque white spot on the basal portion of the posterior part of the rhinophores that are present in H. roo .

There are also clear anatomical differences between H. roo , H. confetti , H. kanga and H. infucata . All four species have bluish pigment and yellow spots. In H. roo and H. infucata , the markings on the gill branches are red, whereas they are deep blue in H. kanga and H. confetti . In H. infucata , the red pigment on the gills is found on the gill rachis and pinnae, whereas in H. roo there is red pigment on the inner gill rachis and in two lines on the outer edge, with red and opaque white markings in between the two outer lines. The rhinophores of H. roo have an opaque white spot on the inner side of the base that is absent in H. infucata . The sides of the body of H. roo are higher than in H. infucata , and the mantle margin is narrower. Also, H. infucata has a broad posterior end of the notum rather than a tapered posterior lobe found in H. roo .

There are differences in the arrangement of mantle glands in the species within this clade. In H. roo and H. zephyra there are usually anterior and posterior mantle glands, but anterior glands may also be lacking in some specimens of H. roo . Hypselodoris confetti and H. nigrostriata have mantle glands all around the mantle margin, whereas H. kanga has only posterior glands. The shape of the jaw rodlets and radular teeth is also similar in H. roo , H. zephyra , H. confetti and H. kanga , but the number of teeth varies slightly.

As noted above, in the reproductive system of H. confetti the receptaculum seminis is situated immediately adjacent to the bursa copulatrix, whereas in H. roo , H. zephyra and H. nigrostriata , it is situated more proximally on the vagina ( Rudman, 1977; Gosliner & Johnson 1999; present study).