title: Diversity and composition of estuarine and lagoonal fish assemblages of Socotra Island, Yemen.
abstract: Estuarine and lagoonal surveys of Socotra Island and selected sites on the Hadhramout coast of Yemen were conducted with the objective of documenting and analysing fish diversity and assemblage structure. A total of 74 species in 35 families were recorded, among which 65 species in 32 families were from Socotra and 20 species in 17 families were from mainland Yemen. Twenty-one species represent new faunal records for Socotra. Including historic records re-examined in this study, the total fish species richness of estuaries and lagoons of Socotra Island reaches 76, which is relatively high compared to species inventories of well-researched coastal estuaries in southern Africa. Five species dominate the occurrence and abundance frequencies: Terapon jarbua, Hyporhamphus sindensis, Aphanius dispar, Ambassis gymnocephala and Chelon macrolepis. Rarefaction and extrapolation analyses suggest that the actual number of fish species inhabiting some of those estuaries might be higher than the one observed. Thus, additional sampling at specific sites should be conducted to record other less conspicuous species. Ordination and multivariate analyses identified four main distinct assemblage clusters. Two groups are geographically well structured and represent northern Socotra and mainland Yemen, respectively. The other two assemblage groups tend to be determined to a greater extent by the synchrony between physical (e.g. estuary opening periods) and biological (e.g. spawning and recruitment periods) variables than by geographical location. Finally, the single intertidal lagoon of Socotra represents by itself a specific fish assemblage. The high proportion of economically important fish species (38) recorded underscores the paramount importance of these coastal water bodies as nursery sites, and for sustaining vital provisioning ecosystem services.
authors.affiliation: Senckenberg Forschungsinstitut und Naturmuseum, Sektion Ichthyologie, Senckenberganlage 25, 60325 Frankfurt am Main, Germany.|Senckenberg Biodiversität und Klima Forschungszentrum (BiK-F), Tropical Marine Ecosystems Group, Senckenberganlage 25, 60325 Frankfurt am Main, Germany.|Université de Bretagne Occidentale, UMR 6539, CNRS/IRD/UBO, Laboratoire des Sciences de l'Environnement Marin LEMAR, Institut Universitaire Européen de la Mer IUEM, Rue Dumont d'Urville, 29280 Plouzané, France.|Kyoto University, Field Science Education and Research Center (FSERC), Educational Unit for Studies on Connectivity of Hills, Humans and Oceans (CoHHO), Oiwake-cho, Kitashirakawa, Sakyo-ku, 606-8502 Kyoto, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Lavergne
authors.affiliation: Senckenberg Forschungsinstitut und Naturmuseum, Sektion Ichthyologie, Senckenberganlage 25, 60325 Frankfurt am Main, Germany.|Senckenberg Biodiversität und Klima Forschungszentrum (BiK-F), Tropical Marine Ecosystems Group, Senckenberganlage 25, 60325 Frankfurt am Main, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Zajonz
authors.affiliation: Senckenberg Forschungsinstitut und Naturmuseum, Sektion Ichthyologie, Senckenberganlage 25, 60325 Frankfurt am Main, Germany.|Qatar Museums, P. O. Box 2777, Doha, Qatar.
authors.forename: F
authors.initials: F
authors.lastname: Krupp
authors.affiliation: Senckenberg Biodiversität und Klima Forschungszentrum (BiK-F), Tropical Marine Ecosystems Group, Senckenberganlage 25, 60325 Frankfurt am Main, Germany.|Environmental Protection Authority, Socotra Branch, Hadibo, Yemen.
authors.forename: F
authors.initials: F
authors.lastname: Naseeb
authors.affiliation: Senckenberg Biodiversität und Klima Forschungszentrum (BiK-F), Tropical Marine Ecosystems Group, Senckenberganlage 25, 60325 Frankfurt am Main, Germany.|Hadhramout University of Science and Technology, Department of Marine Fisheries and Resources, Marine Biology Division, Al-Mukalla, Yemen.
authors.forename: M S
authors.initials: MS
authors.lastname: Aideed
mesh_terms: D000818:Animals; D044822:Biodiversity; D017753:Ecosystem; D063366:Estuaries; D005399:Fishes; D062312:Islands; D010473:Perciformes; D015006:Yemen
keywords: Gulf of Aden; Socotra Island; estuaries; fish assemblages; species diversity; species richness