Pseudolepetodrilus costaricensis, Bathyacmaea, Paralepetopsis and Cocculina from Costa Rica geothermal vents
NEWS - The researchers established three new species and one new genus: Lisa Levin deep-sea limpet (Bathyacmaea levinae), confuse true limpet (Paralepetopsis variabilis), methane deep-sea limpet (Cocculina methane) and Costa Rica false hydrothermal vent limpet (Pseudolepetodrilus costaricensis gen. et sp. nov).
Chemosynthesis-based ecosystems, such as hydrothermal vents and hydrocarbon seeps, host unique, diverse and continuously emerging life forms. The researchers highlighted the unique gastropod fauna and the biodiversity of chemosynthesis-based deep-sea ecosystems.
Limpets were collected from Pacific Costa Rica Margin hydrocarbon seeps during three cruises from 2017 to 2019. Genetic and morphological analyses revealed species in the genera Bathyacmaea Okutani, Tsuchida & Fujikura (1992), Paralepetopsis McLean (1990), Cocculina Dall (1882) and the family Lepetodrilidae McLean (1988).
B. levinae was collected from the Jaco Scar and Quepos Seep hydrocarbon seeps in the Pacific Costa Rica Margin. Samples were taken from mussels and tubeworms at depths of 1400-1890 meters. Named after Dr. Lisa A. Levin of the Scripps Institute of Oceanography for her contributions to deep-sea knowledge, especially hydrocarbon seeps.
B. levinae was diagnosed by its flat and serrated radular teeth, tall and conical shell with no obvious axial carvings. The sample is the only Bathyacmaea species known from the Eastern Pacific Ocean.
P. variabilis was collected from the Jaco Scar, Quepos Seep, Mound 11 and Mound 12 hydrocarbon seeps in the Pacific Costa Rica Margin. Samples were taken from shellfish, tubeworms and rocks at depths of 995-1860 meters. Specimens were also recovered and genetically characterized from the Pescadero Basin hydrocarbon seeps collected by the ROV Tiburon at a depth of 2000 meters.
P. variabilis is diagnosed by its oval, white and semi-transparent shell that exhibits fine radial growth rings. The species also exhibits two short head tentacles (not extending beyond the outer shell edge) that are located low on the head. The soft tissue is yellowish white.
However, the most reliable means of diagnosis is through DNA characterization, as the morphology is highly variable within this species and overlaps with other known species in the genus.
P. costaricensis was confirmed from the Jaco Scar hydrocarbon seep in the Pacific Costa Rica Margin. Samples were taken from tubeworms at a depth of 1760 meters. The generic name means false Lepetodrilus (pseudo), given its physical resemblance to species of the genus Lepetodrilus.
The species epithet costaricensis refers to the Pacific Costa Rica Margin, where the species and genus were first discovered. P. costaricensis was diagnosed by the unique “wing” shaped first major lateral tooth on the radula and by genetic characterization of the mitochondrial CO1 gene.
C. methane from the Quepos Seep, Mound 12, Jaco Scar and Mound Jaguar hydrocarbon seeps in the Pacific Costa Rica Margin. Samples were taken from shells, wood, tubeworms and bones at depths of 1408-2000 meters. This species is among the deepest known Cocculina.
The species epithet methane refers to the hydrocarbon seep. This habitat type is important, as all other known Cocculina species occur in inactive hydrothermal vents or organic waterfalls. C. methane is diagnosed by its golden brown periostracum and is distinguished from C. japonica by its mitochondrial CO1 barcoding.
Original research
Betters MJ, Cortés J, Cordes EE (2024). New species and records of limpets (Mollusca, Gastropoda) from the Pacific Costa Rica Margin. ZooKeys 1214: 281-324, DOI:10.3897/zookeys.1214.128594
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