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| Zancleopsis grandis Schuchert & Collins, 2024 DOI: 10.35929/RSZ.0113 |
Abstract
This work is a supplement of our previous study (Schuchert & Collins, 2021) on hydromedusae observed and collected during night-time dives in the Gulf Stream off Florida. Close-up photos and collection of selected specimens for DNA extraction and 16S barcode sequencing permitted us to distinguish 49 distinct morphotypes or species of hydromedusae. Eighteen of them are new additions to the ones reported in our 2021 paper. Seven potential species of the 49 were only identified to the genus level, one to the family level. Two new species are described: Zancleopsis grandis sp. nov. and Melicertum tropicalis sp. nov. 16S sequences permitted us to identify the previously unknown subadult medusa of Podocoryna martinicana Galea & Ferry, 2013. Three species are new records for the Northwest Atlantic: Leuckartiara adnata Pagès, Gili & Bouillon, 1992, Corymorpha valdiviae (Vanhöffen, 1911), and Cnidocodon leopoldi Bouillon, 1978. The 16S data indicated the potential presence of cryptic species in Thecocodium quadratum (Werner, 1965), Laodicea undulata (Forbes & Goodsir, 1853), Orchistoma pileus (Lesson, 1843), and Pseudaegina rhodina (Haeckel, 1879).
KEYWORDS: 16S DNA barcodes, blackwater diving, Cnidaria, Florida, Hydrozoa, taxonomy
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| Zancleopsis grandis sp. nov. Holotype, BFLA4559, total height size 29 mm. The brownish objects are crustaceans. Structural details: green arrows – the same individual capitulum; red arrows – filiform tentacles, blue arrows – broken ends of the long tentacles, yellow arrows – developmental zone of the side-branches, purple arrow – gonad folds. (A) Lateral view. (B) Manubrium in lateral view. (C-D) Tentacle details. (E-F) Partially relaxed filiform and branched tentacles, the axis of the medusa is horizontal. |
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| Zancleopsis grandis sp. nov. Paratype, BFLA4561, size 25 mm, tentacles and capitula relaxed; green arrows indicate branched tentacles, blue arrows the shorter, filiform tentacles. (A) Lateral view. (B) View on velar opening, the green arrow points to incipient side-branches of a long tentacle. (C) Long tentacle region with large capitula. (D) Higher magnification of capitula. Photos by Linda Ianniello. |
Zancleopsis grandis sp. nov.
Zancleopsis dichotoma. – Bigelow, 1938: 102, figs 1-2. [not Zancleopsis dichotoma (Mayer, 1900)].
Type locality: USA, Florida, about 10 km east of Palm Beach; ...; depth 10 m.
Etymology: The specific epithet “grandis” refers to the relatively large size of this medusa and to the very large capitula of the tentacular side branches.
Diagnosis: Zancleopsis medusa with total bell height up to 29 mm, with large apical process, with two long tentacles with abaxial side branches, the latter ending in very large capitula, much larger than marginal bulbs, spherical or ovoid depending on state of contraction, other two tentacles relatively long, tapering, without swollen end or capitulum; gonads in vertical folds.
Peter Schuchert and Richard Collins. 2024. Additional Observations on Hydromedusae during Night Dives in the Gulf Stream. Revue suisse de Zoologie. 131(1):43-120. DOI: 10.35929/RSZ.0113