Vol. 62, 2023
(update: 2023.10.05)
Integrative Systematics and
Biogeography of the Hydrozoans (Leptothecata: Eirenidae) Eirene menoni
Kramp, 1953 and Eirene lacteoides
Kubota and Horita, 1992 from Japan
and China with Comments on Pacific Ocean Distributions
Gerald
L. Crow1,*,
Brenden S. Holland2,
Gaku Yamamoto3, Shuhei Ikeda4,
Aya Adachi3,
and Kelley Niide5
doi:10.6620/ZS.2023.62-49
1Ocean
Research Explorations, P. O. Box 235926, Honolulu, Hawaii 96823.
*Correspondence: E-mail gcrow@hawaii.edu (Crow)
2Department
of Natural Sciences, College of Natural and Computer Sciences, Hawaii
Pacific University, 45-045 Kamehameha Highway, Kaneohe, Hawaii 96744.
E-mail: bholland@hpu.edu (Holland)
3Enoshima
Aquarium, 2-19-1 Katase Kaigan, Fujisawa, Kanagawa Prefecture 251-0035,
Japan. E-mail: g-yamamoto@enosui.com (Yamamoto); adati@enosui.com
(Adachi)
4Tsuruoka City Kamo Aquarium, 656
Okubo Imaizumi, Tsuruoka, Yamagata Prefecture 997-1206, Japan. E-mail:
s.ikeda@kamo-kurage.jp (Ikeda)
5Waikiki Aquarium, University of Hawaii at Manoa, 2777
Kalakaua Avenue, Honolulu, Hawaii 96815. E-mail: kelleyl@hawaii.edu
(Niide)
(Received 4 November 2022 / Accepted 4
August 2023 / Published 5 October 2023)
Communicated by James D. Reimer
The hydrozoan family Eirenidae is
known scientifically for its morphological plasticity and challenges in
species identification. We used an integrative taxonomic approach based
on morphological, molecular and life history evidence to systematically
assess field-collected medusae of Eirene
menoni Kramp 1953 and captive raised polyps of both E. menoni and E. lacteoides Kubota and Horita
1992. Following morphological review, we updated the genus description
to include the presence of rudimentary bulbs (warts) on the ring canal
in at least eight of the 24 valid Eirene
species. We propose the potential for the mature E. menoni hydrotheca to develop
into a gonotheca. However, this proposal will require additional study
for verification. We provide validated distribution records from the
Indo-Pacific Ocean for E. menoni,
and updated collection records for E.
lacteoides from the Yellow and East China Seas, and public
aquaria-cultured specimens from Japan and Hawaii, using cytochrome c oxidase I (COI) sequences that we generated
and compared with those from GenBank. The COI gene reliably separated four
species, each forming a monophyletic clade with strong bootstrap
support and low mean intraspecific molecular divergences (≤ 1%) within
clades. However, some of the deeper nodes of the tree remained poorly
resolved, and our analysis failed to demonstrate monophyly among
eirenid genera Eirene and Tima. Our integrative taxonomic
approach is essential in confirming species identity within the family
Eirenidae and genus Eirene,
and we have also identified a likely range expansion of E. lacteoides to Hawaii.
Key words: Hydrozoa, Leptomedusae,
Plasticity, Campanulinida hydroid, COI
mtDNA
Citation:
Crow GL, Holland BS, Yamamoto G, Ikeda S, Adachi A, Niide K. 2023.
Integrative systematics and biogeography of the hydrozoans
(Leptothecata: Eirenidae) Eirene
menoni Kramp, 1953 and Eirene
lacteoides Kubota and Horita, 1992 from Japan and China with
comments on Pacific Ocean distributions. Zool Stud 62:49. doi:10.6620/ZS.2023.62-49
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