Reading between the lines: revealing cryptic species diversity and colour patterns in Hypselodoris nudibranchs (Mollusca: Heterobranchia: Chromodorididae) Author Epstein, Hannah E. Author Hallas, Joshua M. Author Johnson, Rebecca Fay Author Lopez, Alessandra Author Gosliner, Terrence M. text Zoological Journal of the Linnean Society 2018 2018-09-14 20 1 1 74 journal article 27363 10.1093/zoolinnean/zly048 49bea467-fac6-484a-9902-05483dec9a52 2632578 urn:lsid:zoobank.org:pub:F0065FD2-417C HYPSELODORIS VIOLACEA GOSLINER & JOHNSON SP. NOV. (FIGS 25G, H, 30B, 31) LSID : urn:lsid:zoobank.org:act: 6D041C56-175A- 4A7C-9219-809DB4C8C03D H y p s e l o d o r i s b u l l o ck i , m i s i d e n t i f i c a t i o n, n o t H. bullockii ( Collingwood, 1881 ) ; Köhler, 2000 ; Sullivan, 2000 ; Lau, 2005 . Figure 31. Hypselodoris violacea Gosliner & Johnson sp. nov. , buccal armature, holotype NMP 0 41286. A, jaw rodlets. B, inner lateral teeth. C, middle lateral teeth. D, outer lateral teeth. Type material Holotype : NMP 0 41286 (formerly CASIZ 182307 ), subsampled for molecular study, dissected, Magic Reef , 11.99°N , 120.08°E , 10 m depth, Bintuan Barangay , Coron , Busuanga Island , Palawan , Philippines , 24 February 2010 , G. Williams. Paratype : CASIZ 0 71286, Manu Manu Island , north end of North Verde Island , Palawan , Philippines , 7–17 m depth, 9 June 1988 , R. Van Syoc . Geographical distribution Known only from Palawan , Philippines and northern Borneo, Malaysia (present study). Etymology The name violacea is Latin for violet, referring to the intense purple body colour that ornaments the body, gill and rhinophores of this species. Description External morphology : Living animals ( Figs 25G, H ) of moderately large size, reaching 50 mm in length. Entire dorsal surface deep, dark purple with thick, solid opaque white band encircling the margin of notum. Sides of body and margin of foot same colour as notum. Ten to eleven unipinnate gill branches on notum that may be divided further basally or apically. Gill branches deep purple. Base of gill pocket well elevated, deep purple. Bulb and base of rhinophores deep purple throughout. Bulb with ~31 densely packed lamellae. Base of rhinophore sheath deep purple. Mantle glands : Mantle glands entirely absent from mantle margin. Buccal armature : Muscular portion of buccal mass about equal in size with oral tube. Chitinous labial cuticle found at anterior end of muscular portion of the buccal mass bearing numerous jaw rodlets ( Fig. 31A ). Rodlets narrow and short with long base and evenly curved, with single, acutely pointed apex. Radular formula of holotype (CASIZ 182307) 66 × 103.0.103. Rachidian row of teeth absent ( Fig. 31B ). Innermost lateral teeth having one to three short denticles on inner of bifid primary cusp and one denticle on the outer side of the bifid cusp. Outer cusp of bifid cusps much shorter than inner one. Next several laterals lacking inner denticles possessing primary bifid cusps and zero or one outer denticle. Midlateral teeth ( Fig. 31C ) all lacking inner denticles but with five or six prominent outer denticles. Outermost teeth ( Fig. 31D ) having a narrower base and having four or five outer denticles. Reproductive system : Reproductive organs of the holotype fully mature ( Fig. 30B ). Ampulla thick, tubular and curved, narrowing somewhat before bifurcating into oviduct and vas deferens. Short oviduct entering female gland mass near albumen gland. Prostatic proximal portion of vas deferens long, convoluted, curved and thick and narrowing abruptly as it transitions into muscular ejaculatory portion. Ejaculatory portion moderately short curved, narrow, entering moderately long, wider penial bulb. Penial bulb adjacent to straight, moderately 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 long vagina leading to small, straight receptaculum seminis and larger spherical, thin-walled bursa copulatrix. Receptaculum seminis appressed against vagina in distal half of vaginal length. Moderately short uterine duct emerging from vagina adjacent to receptaculum and entering female gland mass near the albumen gland. Remarks The differences between H. violacea and other closely related species are discussed above in the remarks section of H. variobranchia .