Population characteristics, space use and habitat associations of the seahorse Hippocampus reidi (Teleostei: Syngnathidae)

Abstract

This paper provides a case study of a threatened seahorse species, Hippocampus reidi, highlighting the importance of using ecological information to assist conservation and management initiatives. Underwater visual sighting data (50 x 2m transect) gathered along the NE, SE and S portions of the Brazilian coast revealed an unequal distribution across localities, perhaps related to harvesting pressure, and a mean density of 0.026 ind.m -2 . Our findings suggest some restricted spatial use by H. reidi, which was consistent with its estimated home range, and with re-sighting of specimens. Reproduction was recorded year-round, however productive peaks may exist. Components of habitat structure mostly used as anchoring points were mangrove plants, macroalgae, cnidarians, seagrass, sponges, and bryozoans. Conservation recommendations include: further characterization and mapping of habitats; assessment of availability and condition of microhabitats in selected areas, and studies on dispersal routes during initial life stages.Neste artigo apresenta-se um estudo de caso de uma espécie ameaçada de cavalo-marinho, Hippocampus reidi, enfatizando a importância de utilizar informações ecológicas nas ações de conservação e manejo. Dados de censo visual (transectos de 50 x 2m) obtidos nas porções NE, SE e S da costa brasileira revelaram uma distribuição heterogênea entre as localidades, talvez relacionada à pressão de coleta, e uma densidade média de 0.026 ind.m -2. Os resultados sugerem limitação no uso do espaço por H. reidi (consistente com a área vital estimada e com a re-avistagem de exemplares) e que a reprodução ocorre o ano inteiro, embora com possíveis picos. Os componentes da estrutura do habitat mais freqüentemente utilizados como pontos de ancoragem pelos cavalos-marinhos foram vegetação de mangue, macroalgas, cnidários, capim marinho e briozoários. Recomendações conservacionistas incluem caracterização adicional e mapeamento de habitats; avaliação da disponibilidade e condição dos microhabitats em áreas selecionadas, e estudos sobre rotas de dispersão durante as fases iniciais de vida.

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

“…They inhabit a variety of habitats such as coral reefs, seagrass meadows, mangroves, estuaries and open bottom habitats, although their distribution can be patchy and sparse (Perante, 2002;Foster & Vincen, 2004;Rosa et al, 2007). Seahorses are weak swimmers and tend to anchor themselves to vegetation or the substrate using a strong prehensile tail (Kendrick & Hyndes, 2005), and rely on prey coming within close range instead of actively pursuing them Lourie et al, 2004;Felício et al, 2006).…”

“…Listing seahorses on CITES Appendix II obliges signatory countries to determine sustainable levels of trade. Managing wild populations requires information on population status and extraction levels as well as the space use and ecology (Rosa et al, 2007). The Indo-Pacific region contains the highest diversity of marine fish including seahorses but also has the greatest threats to habitats and species (Allen, 2008) with welldocumented seahorse fisheries supplying both the TCM and aquarium trades (Giles et al, 2006;Meeuwig et al, 2006;O'Donnell et al, 2010;Perry et al, 2010).…”

Novel sex-related characteristics of the longsnout seahorse Hippocampus reidi Ginsburg, 1933

“…Hippocampus reidi is a slender-body species with variable colour patterns, consisting of at least six distinct background colours (Rosa et al, 2002), often profusely spotted with dark dots and numerous tiny white dots (especially on the tail), and may also have pale saddles across dorsolateral surfaces (see Lourie et al, 1999Lourie et al, , 2004. As most seahorse species studied to date (see , for a review), H. reidi was inferred to be monogamous and forming pair bonds (Rosa et al, 2007). Published data on sex-related differences in the species are limited to the brood pouch and height Rosa et al, 2007).…”

“…As most seahorse species studied to date (see , for a review), H. reidi was inferred to be monogamous and forming pair bonds (Rosa et al, 2007). Published data on sex-related differences in the species are limited to the brood pouch and height Rosa et al, 2007).…”

“…Data used in the present study were gathered from October 2005 to July 2007 at four estuaries in Northeastern Brazil: (1) the Camurupim/Cardoso estuarine complex (02°53'S-02°58'S, 41°24'W-41°28'W), Delta do Parnaíba Environmental Protection Area, State of Piauí, as described in Rosa et al (2007) and Mai & Rosa (2009); (2) the Mamanguape estuary, Barra de Mamanguape Environmental Protected Area (06°43'S-06°51'S, 35°07'W-34°54'W), State of Paraíba (as described in Rosa et al, 2007); (3) the Itapessoca estuary (07°37'S-07°41'S, 34°50'W-34°55'W , described in Rosa et al, 2007) and (4) the rio Formoso estuary (08°35'S-08°45'S, 35°5'W-35°10'W), both in the State of Pernambuco.…”