Conservation value of Codium tenue habitat for the endangered Knysna seahorse Hippocampus capensis
| Autor: | Alan N. Hodgson, Nina M de Villiers, Louw Claassens, Cassandra Barker |
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| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
Male Conservation of Natural Resources Endangered species Aquatic Science 010603 evolutionary biology 01 natural sciences Population density Syngnathidae South Africa Animal science Hippocampus capensis Animals Sex Ratio Ecology Evolution Behavior and Systematics Ecosystem geography geography.geographical_feature_category biology 010604 marine biology & hydrobiology Endangered Species Estuary biology.organism_classification Smegmamorpha Habitat Seahorse Female Seasons Estuaries Sex ratio |
| Zdroj: | Journal of fish biologyREFERENCES. 95(6) |
| ISSN: | 1095-8649 |
| Popis: | We investigated the density and size structure of the endangered Knysna seahorse Hippocampus capensis in the macroalga Codium tenue at three sites in a residential marina estate in the Knysna Estuary, South Africa, over an 18 month period from March 2017 to August 2018. Seahorses were present in C. tenue throughout the year. Average (± SE) densities of 0.33 (± 0.03) and 0.23 (± 0.03) seahorses per kg of C. tenue were found for 2017 and 2018 respectively. Density did not vary across sites but varied significantly across months with a decreasing trend from summer to spring. The average (± SE) adult seahorse height was 75.16 mm (± 0.63 mm) and 69.09 mm (± 0.64 mm) and mass was 2.05 g (± 0.04 g) and 1.65 g (± 0.04 g) for males and females, respectively, and an even sex ratio was observed throughout the sampling period. Height varied across months, with significantly smaller seahorses found in June and August of 2017. Tail length was highly correlated with height and therefore can serve as a potential proxy for determining the height of H. capensis. This study showed that C. tenue is consistently utilised by Knysna seahorse and should therefore be considered an important habitat to protect and facilitate the ongoing conservation of this endangered seahorse species. |
| Databáze: | OpenAIRE |
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