Habitat Preference and Population Structure of Two Data Deficient Seahorse (Syngnathidae) Species

Abstract

Ecological studies of seahorses are sparse in the Indian Ocean. The vulnerability of seahorses to overfishing and increased anthropogenic impacts on coastal habitats necessitates better management of wild seahorse populations that in turn requires understanding habitat preferences and population structure. The distribution patterns and population structure of two species of seahorse (Hippocampus fuscus and H. spinosissimus) were assessed for the first time in a tropical estuary in north-western Sri Lanka. Both species have previously not been studied in the wild and have not been known to occur in estuaries.H. fuscus was the more abundant and widely distributed species, and was significantly larger than H. spinosissimus. Both species had significant differences in size between sexes, and the mean height was towards the lower end of the range know for both species. Some sexually mature males were smaller than the size reported in the literature. DOI: http://doi.org/10.4038/ouslj.v12i2.7408 N. Perera, D. D. G. L. Dahanayaka and S. Udagedara Seahorses occurred in low densities with patchy distribution, with abundance being higher in areas with the seagrass species Enhalus acoroides and Cymodocea serrulata that appear to be the favored habitat of seahorses within the study area. _______________________

Abundance, Distribution, and Habitat Preference of Syngnathid Species in Sabaudia Lake (Tyrrhenian Sea)

“…This study provides the first evidence of the occurrence of Hippocampus guttulatus, H. hippocampus, Syngnathus abaster, and Nerophis ophidion in Sabaudia Lake. The number of individuals of four species was relatively high considering the extension of investigated habitats, and the observed scattered distribution is consistent with that observed in previous studies e.g., [6,16,39,40], suggesting that syngnathids display patchy distributions even on small spatial scales. It should be noted, however, that the numbers recorded in this work are conservative estimates of the species distributions in habitats and are certainly strongly influenced by the sampling method used.…”

Chemical constituents, pharmacological activities and quality evaluation methods of genus Hippocampus: A comprehensive review

“…Genus Hippocampus , a kind of marine teleost fish, belongs to the Syngnatidae family, which also includes pipefish and seadragons ( Vitturi & Catalano, 1988 ), and mainly distributed in the Indian, Atlantic and Pacific oceans ( Perera, Dahanayaka, & Udagedara, 2017 ). Hippocampus generally inhabits shallow waters above 30 m in tropical and temperate regions, favoring seagrasses and macroalgal ( Pereira, Silveira, & Abilhoa, 2018 ), which have a suite of unusual biological characteristics shared by these species including male pregnancy and monogamy ( Holt, Fazeli, & Otero-Ferrer, 2021 ).…”

Mapping seahorses in a Brazilian estuary: mangrove structures as key predictors for distribution and habitat preference

“…Seahorse species have different habitat dependency levels and preferences ( Zhang & Vincent, 2018 ), and are generally found in shallow coastal habitats, including transitional ecosystems, such as estuaries ( Bell et al, 2003 ; Claassens & Hodgson, 2018 ). Twelve species of seahorses have been recorded in estuaries ( Harasti, Martin-Smith & Gladstone, 2012 ; Lourie et al, 2004 ; Perera, Dahanayaka & Udagedara, 2017 ; Rose et al, 2019 ; Yip et al, 2015 ), including one that is exclusively estuarine— Hippocampus capensis ( Claassens & Harasti, 2020 ). Habitat degradation and loss are among the greatest threats to seahorses ( Vincent, Foster & Koldewey, 2011 ) and the case of estuaries raises particular concern since they are considered one of the most imperiled marine ecosystems globally ( Kennish, 2002 ).…”