Naisdoris vitiligata, Paz-Sedano & Cobb & Gosliner & Pola, 2024

Paz-Sedano, Sofia, Cobb, Gary, Gosliner, Terrence M. & Pola, Marta, 2024, Filling gaps in the knowledge of Goniodorididae taxa (Mollusca, Gastropoda, Nudibranchia) with description of seven new species, Zootaxa 5443 (4), pp. 523-547 : 542-543

Naisdoris vitiligata sp. nov.

( Figs. 7E‒F , 6G‒H , 8H‒J )

Zoobank: urn:lsid:zoobank.org:act:B31C27EF-752A-4A97-ABEB-5F77074C902B

Okenia liklik — Anderson (2016)

Okenia cf. liklik — Behrens (2019)

Naisdoris sp. F — Paz-Sedano et al. (2024)

Type material. Holotype. ZCR.MOL.15410, Hantu Island , Singapore, 15 m depth, 28 January 2018, col. by C. H. Toh, 96% EtOH, dissected ( SEM: radula, labial cuticle, penis) . Paratypes. ZCR.MOL.15411, Hantu Island , Singapore, 15 m depth, 28 January 2018, col. by C. H. Toh, 96% EtOH, dissected ( SEM: labial cuticle, penis) ; CASIZ 186126 , Ladder dive site, Caban Island, Maricaban Island, Batangas Province, the Philippines, 13.6842 ºN 120.84119 ºE, 10 May 2011, col. by T. Gosliner.

External morphology ( Figs. 7E‒F ). Preserved specimens 2–3 mm in length. Body elongated, notal border well developed, markedly serrated due to presence of internal spicules. Ends of large spicules resemble small papillae from outside of specimens. Middorsal crest also supported by spicules. Two elongated, conical, and thin papillae located in front of rhinophores, one on each side. Tips of anterior papillae thinner than bases. Posterior part of mantle with a small extension that seems a short posterior papilla on each side of body mantle. Anterior papillae slightly larger than posterior ones. Rhinophores non-retractile, elongated, and slender, bearing 12–13 lamellae oriented to posterior part. Rhinophoral sheath absent. Four thin, simple gill branches form a semicircle around anus, two anteriormost sharing common stalk. One tentacular oral tentacle on each side of mouth, short and muscular, somehow triangular shape. Reproductive opening located on first third of right lateral side of body. Mantle covered by spicules.

Color pattern ( Figs. 7E‒F ). Body pink. Large white patch in the dorsal part of the body, may be surrounded by a thin reddish-brown line. Mantle margin with light yellow patches, matching with spikes that make it serrated. Anteriormost papillae translucent yellow at tip, light yellow at base. Posteriormost papillae and gill branches with yellow tips and pink base. Rhinophores same color as dorsal reddish-brown line, may have a bright yellow band. Most external lamellae with yellow tones.

Foregut anatomy ( Figs. 6G , 8H‒I ). Buccal bulb thick and muscular ( Fig. 6G ). Elongated, wide, dorsal buccal pump expanding posteriorly. Small radular sac located ventrally, expanding backwards. Esophagus begins from buccal bulb behind buccal pump. Salivary glands very small, rounded, located at junction of esophagus with buccal bulb. Nervous system covers this junction.Esophagus continues posteriorly and inserts into digestive-hermaphroditic gland. Labial cuticle surrounds lips and expands within buccal pump. Radular formula 14 × 1.1.0.1.1. Inner lateral tooth with single large and thin cusp, and wide, rectangular base ( Fig. 8H ). Cusp large and pointed, masticatory margin with 12–21 very small, pointed denticles ( Fig. 8H ). Denticles located at middle part of masticatory margin larger than lateral ones. Outer base ends in somewhat prominent wing. Outer lateral tooth much smaller, rectangular with two thin hooks, upper hook large and lower one very small ( Fig. 8I ).

Reproductive system ( Figs. 6H , 8J ). Reproductive system located at anterior-third of body. Thin hermaphroditic duct begins at ovotestis, located inside digestive-hermaphroditic gland. Hermaphroditic duct expands into big and oval ampulla. Postampullary duct emerges from ampulla and divides into two different, thin ducts. Short, oviduct enters inside female gland mass. Second duct connects with first portion of prostate. Prostate sausage-shaped. Prostate folds, narrows and become a very thin vas deferens. Prostate and vas deferens have similar length. Vas deferens continues and expands to ejaculatory duct. Penis with small, hooked penial spines ( Fig. 8J ). Vagina small, slightly wider than vas deferens. Vagina connects with rounded bursa copulatrix. From middle of vagina arises a duct which connects with rounded receptaculum seminis. At same point of division of ducts arises thin uterine duct that enters female gland mass. Receptaculum seminis similar in size to bursa copulatrix.

Etymology. “vitiligata ” refers to the distinctive white patch on the dorsum of the species, in Latin vitiligo refers to the lack of pigmentation in an area of the skin.

Distribution. Indonesia ( Behrens 2019), the Philippines ( Anderson 2016; present study) and Singapore (present study)

Natural history. This species is found on flat rubble plains in about 30 m of water.

Remarks. The species N. vitiligata sp. nov. resembles N. liklik and N. labalsaensis sp. nov. by its pink background coloration but differs in the color pattern of the mid-dorsal part of the body ( Gosliner 2004). Naisdoris vitiligata sp. nov. is distinguished by its large white patch in the middle of dorsum while N. labalsaensis sp. nov. has a pink mid-dorsal line with yellow and dark brown spots. The rhinophores are dark in N. vitiligata sp. nov., pink with brown tips in N. labalsaensis sp. nov. and pink with orangish tips in N. liklik ( Gosliner 2004) . Naisdoris vitiligata sp. nov. has serrated margin and lacks the dorsal papilla that are present in N. liklik ( Gosliner 2004) . Internally, in N. vitiligata sp. nov. the cusp located at the external part of the outer lateral tooth has a hooked point, larger and more evident than in N. liklik and N. labalsaensis sp. nov. ( Gosliner 2004). Moreover, N. vitiligata sp. nov. differs from N. labalsaensis sp. nov. by the length of the vagina, uterine duct, and buccal pump, which are much shorter in N. vitiligata sp. nov. than in N. labalsaensis sp. nov. The ducts that connect with the bursa copulatrix, the receptaculum seminis and the uterine duct arises from the same point in N. vitiligata sp. nov. while in N. liklik the uterine duct arises from the base of the vagina ( Gosliner 2004).

Figures

FIGURE 6. Buccal bulb and reproductive system. A–B. Murphydoris polkadotsa sp. nov. (QM MO 86038). A. Buccal bulb. B. Reproductive system. C–D. Naisdoris aurornata sp. nov. (CASIZ 186113). C. Buccal bulb. D. Reproductive system. E–F. Naisdoris labalsaensis sp. nov. (WAM S72700). E. Buccal bulb. F. Reproductive system. G–H. Naisdoris vitiligata sp. nov. (ZCR.MOL.15410). G. Buccal bulb. H. Reproductive system. Abbreviations: am, ampulla; bc, bursa copulatrix; bp, buccal pump; fgm, female gland mass; hd, hermaphroditic duct; oe, esophagus; op, esophageal pump; p, penis; pr, prostate; ra, radular sac; rs, receptaculum seminis; sgl, salivary gland; ud, uterine duct; va, vagina; vd, vas deferens. Scale bars: 1 mm.

FIGURE 7. Living animals. A. Naisdoris aurornata sp. nov. (CASIZ 186113) B. Naisdoris aurornata sp. nov. (CASIZ 186128). C. Naisdoris labalsaensis sp. nov. (WAM S72659). D. Naisdoris labalsaensis sp. nov. (WAM S72657). E. Naisdoris vitiligata sp. nov. (CASIZ 186126). F. Naisdoris vitiligata sp. nov. (ZCR.MOL.15410). (Photos A, B, E by T. Gosliner, C, D by G. Cobb, F by T. C. Hoon)

FIGURE 8. Scanning electron micrographs and light microscope photographs of cuticles, radulae and penis. A‒B. Naisdoris aurornata sp. nov. (CASIZ 186113). A. Detail of inner lateral teeth. B. Detail of outer lateral teeth. C‒G. Naisdoris labalsaensis sp. nov. C. Detail of labial cuticle elements (WAM S72659). D. Detail of inner lateral teeth with denticles (WAM S72657). E. Detail of inner lateral teeth without denticles (WAM S72100). F. Detail of outer lateral teeth (WAM S72659). G. Detail of penial spines (QM MO 86036). H‒J. Naisdoris vitiligata sp. nov. (ZCR.MOL.15410). H. Detail of inner lateral teeth. I. Detail of outer lateral teeth. J. Detail penial spines. Scale bars: A, B, D, E, H: 20 μm; C, 5 μm; F, G, I, J: 10 μm.