Are we overlooking the impact of cirriped barnacle, Octolasmis sp. infestations on decapod crustaceans? Morphological and molecular insights from the disease investigation
Saravanan, K.; Praveenraj, J.; Kiruba-Sankar, R.; Biswas, U.; Devi, V.; Kumar, T.S.; Sudhagar, A.; Seth, J.K. (2025). Are we overlooking the impact of cirriped barnacle, Octolasmis sp. infestations on decapod crustaceans? Morphological and molecular insights from the disease investigation. Biologia 80(6): 1353-1366. https://dx.doi.org/10.1007/s11756-025-01899-3
In: Biologia. Springer: Bratislava. ISSN 0006-3088; e-ISSN 1336-9563, more
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| Authors | | Top |
- Saravanan, K.
- Praveenraj, J.
- Kiruba-Sankar, R.
- Biswas, U.
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- Devi, V.
- Kumar, T.S.
- Sudhagar, A.
- Seth, J.K.
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| Abstract |
The present study investigates the impact of cirriped barnacle, Octolasmis sp. on the culture of mud crab, Scylla spp.. Octolasmis sp., a pedunculate barnacle commonly found attached to the gill chambers of decapods, often regarded as ectocommensal. Disease outbreaks were recorded in three mud crab farms located at South Andaman, Andaman and Nicobar Islands, India, resulted up to 30% mortality. Morphological, microscopic, and molecular analyses excluded the possibility of other potential crab pathogens and confirmed the presence of heavy infestations of Octolasmis sp., on the gills of affected crabs (peak mean intensity of 412 ± 58 parasites per crab), leading to respiratory distress and mortality. The morphometric analysis identified the distinct structures, including the cirri, capitulum, and peduncle. DNA barcoding of the parasite’s cytochrome c oxidase subunit I (COI) gene revealed over 83% sequence identity with Octolasmis spp. from other regions, further supported by phylogenetic analysis. Scanning electron microscopy revealed the attachment of barnacle to the gills of crab through peduncles. Despite optimal water quality parameters, the infestations persisted, emphasising the resilience of Octolasmis sp. The study also noted the barnacle’s rapid reproduction and year-round infestations, especially in larger, mature crabs. Although Octolasmis spp. are generally considered an ectocommensal, high infestation levels can significantly harm the host. This research provides valuable molecular data on this overlooked barnacle species and extends its known geographic distribution. It underscores the need for further research on the epidemiology, biosecurity, and control strategies to mitigate the parasite’s negative impact on crab farming. |
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