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| Croisettea kalaukapuae F.P. Cabrera & A.R. Sherwood in Cabrera, Huisman, Spalding, .. et Sherwood, 2022. |
ABSTRACT
Recent investigations into the species diversity of red blades in Hawai‘i have yielded several specimens of Kallymeniaceae from Hawaiian Mesophotic Coral Ecosystems. Our combined morphological and mitochondrial COI-5P and plastid rbcL phylogenetic analyses indicated widespread cryptic diversity among those specimens commonly identified as Kallymenia sensu lato based on morphology. These analyses resolved four unique genetic lineages of Hawaiian taxa in the genus Croisettea, which are all restricted to the lower mesophotic depths (c. 60–150 m). Croisettea currently includes three described species distributed in the North Atlantic, Indian and South Pacific Oceans, and the Mediterranean Sea. Croisettea is a new genus record for the Hawaiian Islands, expanding its biogeographic range to the North Pacific. The genus has now been enlarged to include seven species comprising previously described taxa as well as four new Hawaiian taxa (C. kalaukapuae sp. nov., C. haukoaweo sp. nov., C. ohelouliuli sp. nov. and C. pakualapa sp. nov.). The known distributions of the Hawaiian Croisettea species are restricted to areas around their type localities. Although this pattern hints at a remarkable degree of endemicity, both across depth gradients in a reef area and among islands, it is also linked to a limited sampling of the group, suggesting that additional species, and more accurate distributional ranges, remain to be detected not only in Hawai‘i but also worldwide.
KEYWORDS: COI-5P, Deepwater, Endemism, Foliose, Molecular-assisted alpha taxonomy, rbcl, Red algae, Red blades, Systematics, Taxonomy
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| Croisettea kalaukapuae sp. nov. [2] Holotype specimen, male gametophyte (BISH 780911) in situ, collected at Papa’āpoho (Lisianski) at 84 m. [3] Paratype specimen (BISH 780917) in situ, collected at Lalo (French Frigate Shoals) at 83 m. [4] Live holotype specimen (BISH 780911), cleaned of epiphytes. [5] Live holotype specimen (BISH 780917), cleaned of epiphytes. [6] Voucher for BISH 780911 (holotype, tetrasporophyte). Scale bar = 5 cm. |
Croisettea kalaukapuae F.P. Cabrera & A.R. Sherwood sp. nov.
Etymology: The species epithet kalaukapuae honours Laura Kalaukapu Low Lucas Thompson (1925–2020) for her advocacy for Hawai‘i’s cultural and natural resources, especially her significant contributions to the creation of the Papahānaumokuākea Marine National Monument, including her role as a founding member of the NWHI Coral Reef Ecosystem Reserve (see Table S3 for more information on how specific nomenclature was developed using traditional Hawaiian naming practices in collaboration with the Papahānaumokuākea Native Hawaiian Cultural Working Group, CWG).
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Croisettea haukoaweo sp. nov. [14] Pressed voucher for BISH 780919 (holotype, vegetative). Croisettea ohelouliuli sp. nov. [17] Pressed voucher for BISH 780920 (holotype, vegetative). [18] Pressed voucher for BISH 780921 (paratype, vegetative). Scale bar = 5 cm. |
Croisettea haukoaweo F.P. Cabrera & A.R. Sherwood sp. nov.
Etymology: The species epithet haukoaweo refers to “the vibrant limu entwined with pūko’ako’a (Halimeda sp.) found in the cool deep waters”. The term ‘hau’ in the name also honours Mr. Skippy Hau, conservationist and retired State of Hawai‘i Division of Aquatic Resources staff on Maui, for his lifetime dedication to the ocean and his community (see Table S3 for more details on how the CWG developed the species name).
Croisettea ohelouliuli F.P. Cabrera & A.R. Sherwood sp. nov.
Etymology: The species epithet ohelouliuli refers to “the dark and vibrant ‘ōhelo” (or algae with no known species attached to it). ‘Ōhelo also describes the colour of the limu in its reference to a mauka (land) plant, Vaccinium reticulatum Smith, and its deep, red-coloured berries and endemicity to Hawai‘i (see Table S3 for more details on how the species name was developed by the CWG).
Croisettea pakualapa F.P. Cabrera & A.R. Sherwood sp. nov.
Etymology: The species epithet pakualapa refers to “a sprawling, tapered limu found on the ridge” (see Table S3 for more details on how the species name was developed by the CWG).
Feresa P. Cabrera, John M. Huisman, Heather L. Spalding, Randall K. Kosaki, Celia M. Smith and Alison R. Sherwood. 2022. Cryptic Diversity in the Genus Croisettea (Kallymeniaceae, Rhodophyta) from Hawaiian Mesophotic Reefs. Phycologia. DOI: 10.1080/00318884.2022.2096823
