Phylogenetic systematics of the genus Cyerce (Mollusca: Heterobranchia: Sacoglossa: Caliphyllidae) from the Pacific and Indian oceans with descriptions of nine new species

Karina Moreno; Sabrina Medrano; Terrence M Gosliner; Nerida G Wilson; Patrick J Krug; Ángel Valdés

doi:10.1093/zoolinnean/zlaf030

Phylogenetic systematics of the genus Cyerce (Mollusca: Heterobranchia: Sacoglossa: Caliphyllidae) from the Pacific and Indian oceans with descriptions of nine new species

Zool J Linn Soc. 2025 May 17;204(1):zlaf030. doi: 10.1093/zoolinnean/zlaf030. eCollection 2025 May.

Authors

Karina Moreno¹, Sabrina Medrano¹, Terrence M Gosliner², Nerida G Wilson^{3

4}, Patrick J Krug⁵, Ángel Valdés¹

Affiliations

¹ Department of Biological Sciences, California State Polytechnic University, Pomona, CA 91768, United States.
² Department of Invertebrate Zoology and Geology, California Academy of Sciences, San Francisco, CA 94118, United States.
³ Collections and Research, Western Australian Museum, Kew Street, Welshpool, Perth, WA 6106, Australia.
⁴ School of Biological Sciences, University of Western Australia, Stirling Hwy, Crawley, Perth, WA 6009, Australia.
⁵ Department of Biological Sciences, California State University, Los Angeles, CA 90032-8201, United States.

PMID: 40386083
PMCID: PMC12084516 (available on 2026-05-17)
DOI: 10.1093/zoolinnean/zlaf030

Abstract

The genus Cyerce Bergh, 1870 has been a model for the study of defensive strategies, including chemical defences, ceratal autotomy, and crypsis or aposematism. Specialization on different algae and diverse genital armatures also make Cyerce a useful system for investigating speciation by host shift versus sexual selection. Here, we review the genus Cyerce in the Pacific and Indian oceans using molecular and morphological data. Two mitochondrial genes (COI and 16S) and one nuclear gene (H3) were sequenced from 154 specimens, including representatives from the Atlantic Ocean. Bayesian and maximum likelihood analyses were used to generate phylogenetic hypotheses. Species delimitation analyses performed on COI sequences recovered 17 genetically distinct Pacific and Indian Ocean species of Cyerce, 10 of which are new to science. Nine new species are named herein (C. takanoi sp. nov., C. katiae sp. nov., C. trowbridgeae sp. nov., C. blackburnae sp. nov., C. tutela sp. nov., C. basi sp. nov., C. whaapi sp. nov., C. goodheartae sp. nov., and C. liliuokalaniae sp. nov.). The 10th species, from the Red Sea, is not named due to the absence of internal anatomical data. These findings increase the species richness in Cyerce by about two-thirds, and demonstrate that even conspicuous taxa harbour considerable cryptic diversity.

Keywords: biodiversity; evolution; molecular phylogeny; penial anatomy; radulae.

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