Cyerce katiae, Moreno & Medrano & Gosliner & Wilson & Krug & Valdés, 2025

Moreno, Karina, Medrano, Sabrina, Gosliner, Terrence M., Wilson, Nerida G., Krug, Patrick J. & Valdés, Ángel, 2025, Phylogenetic systematics of the genus Cyerce Bergh, 1870 (Mollusca: Heterobranchia: Sacoglossa: Caliphyllidae) from the Pacific and Indian oceans with descriptions of nine new species, Zoological Journal of the Linnean Society 204 (1) : -

Cyerce katiae sp.nov.

( Figs 2F, 4C, 8)

LSID: zoobank.org:act: A7A6A023-F563-4F07-8A75- 7A09800DF236.

Cyerce sp. 4 Gosliner et al. 2018: 402; Nakano 2018: 119.

Type material

Holotype: House reef, 3 P Resort, Romblon Province, Philippines, 3 Apr 2017, leg. F. Imhof, 12 mm preserved length, dissected (isolate KM28 , CASIZ 222096 ).

Range

West Pacific Ocean ( Gosliner et al. 2018, Nakano 2018; present paper).

Description

External morphology: Body colour light grey to cream, with dark grey lines creating geometric pattern throughout dorsum ( Fig. 2F). Head colour light grey with dark grey web-like striations throughout; two gold patches near base; small gold spots at forehead. Rhinophores long, bifurcated with minute white specks scattered along margins, translucent light grey. Oral tentacles with similar colour pattern to rhinophores, ventrally located. Pericardium near center of dorsum, with anal papilla located anteriorly. Cerata lobate, inflated, translucent light grey with dark grey web-like striations forming polygons; silvery small white pustules at center of each grey polygon and clustered near the margins of cerata; small gold to dark yellow spots randomly scattered across surface. Cerata increase in size towards posterior end of body; anteriormost cerata lack grey lines. Cerata margin outlined with grey margin and gold spots; conspicuous (probably defensive) glands beneath margin.

Internal morphology: Pharynx about 2 mm in length, buccal bulb and pharyngeal pouch similar in size. Radula with 16 teeth in a 12-mm preserved length specimen ( CASIZ 222096); 8 on descending limb, 8 on ascending limb ( Fig. 8A). Leading tooth about 95 µm in length, elongate, nearly straight, slightly bent, with two rows of ~9 denticles along either side of tooth ( Fig. 8B). Denticles nearly square, curved inwards, with pointed ends. Ascus with about 18 used teeth ( Fig. 8C). Penial opening directly beneath right rhinophore. Penis with penial stylet at opening ( Fig. 4C). Penial stylet hollow, approximately 400 µm long, elongate, slightly curved near the apex, wider at the base.

Ecology Diet unknown.

Etymology

This species is named in honour of Kati Eschweiler who first found this species in Romblon and brought it to the attention of TG.

Remarks

All methods of species delimitation and phylogenetic analyses supported Cyerce katiae sp. nov. as a distinct candidate species ( Fig. 1A; Table 3). Cyerce katiae sp. nov. was recovered as sister to a clade comprising C. nigricans and C. takanoi sp. nov. ( Fig. 1) and shares with C. nigricans and C. takanoi sp. nov. yellow gold spots scattered across the cerata. Internally, specimens of C. takanoi sp. nov. have different radular teeth from those of C. katiae sp. nov. The tip of the teeth cusps in C. takanoi sp. nov. are rounded, whereas they are pointed in C. katiae sp. nov. Moreover the teeth of C. takanoi sp. nov. are much longer and fewer in number than in C. katiae sp. nov. Externally, C. takanoi sp. nov. and C. katiae sp. nov. are also distinct; the cerata of C. takanoi sp. nov. are black with an orange inframarginal band and a white marginal band, whereas the cerata of C. katiae sp. nov. are translucent grey lacking the orange and white bands but instead having a grey margin and gold spots.

Cyerce katiae sp. nov. is also internally and externally morphologically distinct from C. nigricans ; the cerata of C. nigricans are black with a yellow-orange inframarginal band and a white band along the margin, differing from C. katiae sp. nov. The penial stylet in C. katiae sp. nov. is wider at the base, slightly curved, with a blunted tip, whereas the penial stylet in C. nigricans is straight with a pointed triangular tip. The radular morphology of C. katiae sp. nov. also differs from that of C. nigricans , as the tooth cusps are flatter with denticles that have a wider edge than the base; the denticles are also more square-shaped in C. katiae sp. nov. than in C. nigricans , which are more triangular. The cerata of C. katiae sp. nov. are more oval than the fan-shaped cerata observed in C. nigricans and C. takanoi sp. nov. Lastly, the head of C. katiae sp. nov. does not have any of the orange-yellow banding across the rhinophores or head as observed in C. nigricans or in C. takanoi sp. nov. Cyerce katiae sp. nov. is morphologically distinct from all other Cyerce species, as this is the only species to have web-like grey striations forming polygons throughout the body, and cerata with scattered white pustules and gold spots throughout, as well as two distinct gold patches at the base of the head. Therefore, Cyerce katiae sp. nov. is here described as a new species.

Clade 2