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Gomes M, Lopes VM, Mai MG, Paula JR, Bispo R, Batista H, Barraca C, Baylina N, Rosa R, Pimentel MS. Impacts of acute hypoxia on the short-snouted seahorse metabolism and behaviour. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166893. [PMID: 37696409 DOI: 10.1016/j.scitotenv.2023.166893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/31/2023] [Accepted: 09/02/2023] [Indexed: 09/13/2023]
Abstract
Seahorses are one of the most unique and enigmatic animals, recognized as flagship species for several conservation issues. Unfortunately, seahorses' populations have been declining and their unique lifestyle may constrain the ability of these animals to evolve in the future climate scenarios. They inhabit shallow coastal waters that display daily or seasonal environmental fluctuations. Yet, few studies have scrutinized the impacts of climate changes on these iconic species. Within this context, the objective of this work was to test the effects of an extreme hypoxia exposure (~27 % dissolved oxygen for approximately 7 h) on the metabolism, behaviour and food intake of the temperate seahorse Hippocampus hippocampus. Regarding metabolism, hypoxia exposure led to a significant reduction in metabolic rates and an increase in ventilation rates. Seahorses showed signs of movement lethargy under oxygen depletion. The results show that a small but extreme exposure to hypoxia is tolerable by seahorses despite inducing metabolic and behavioural changes, that may jeopardize the future development and survival of these iconic organisms.
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Affiliation(s)
- Matilde Gomes
- MARE - Marine and Environmental Sciences Centre/ARNET-Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal.
| | - Vanessa M Lopes
- MARE - Marine and Environmental Sciences Centre/ARNET-Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal
| | - Monica G Mai
- MARE - Marine and Environmental Sciences Centre/ARNET-Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal
| | - José R Paula
- MARE - Marine and Environmental Sciences Centre/ARNET-Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal; Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal
| | - Regina Bispo
- Center for Mathematics and Applications (NovaMath), FCT NOVA and Department of Mathematics, FCT NOVA, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Hugo Batista
- Oceanário de Lisboa, Esplanada D. Carlos I, 1900-005 Lisbon, Portugal
| | - Catarina Barraca
- Oceanário de Lisboa, Esplanada D. Carlos I, 1900-005 Lisbon, Portugal
| | - Núria Baylina
- Oceanário de Lisboa, Esplanada D. Carlos I, 1900-005 Lisbon, Portugal
| | - Rui Rosa
- MARE - Marine and Environmental Sciences Centre/ARNET-Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal; Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal
| | - Marta S Pimentel
- MARE - Marine and Environmental Sciences Centre/ARNET-Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo 939, 2750-374 Cascais, Portugal; Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal
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Mason HD, Rose E, Gonzalez JE, O'Brien DA. Nocturnal surveys of lined seahorses reveal increased densities and seasonal recruitment patterns. Ecol Evol 2023; 13:e9573. [PMID: 36644702 PMCID: PMC9834011 DOI: 10.1002/ece3.9573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 03/22/2021] [Accepted: 03/24/2021] [Indexed: 01/13/2023] Open
Abstract
Although the nighttime ecology of organisms remains understudied, nocturnal surveys play an integral part in assessing fish assemblages and the selective forces shaping them. Eleuthera (Bahamas) contains an unusual population of lined seahorses (Hippocampus erectus) in an anchialine lake, possessing morphological characteristics distinct from those found in the ocean. Population surveys for seahorses and their potential predators were conducted at midnight and midday during wet and dry seasons, with belt transects perpendicular to the shoreline that increased in depth away from shore. Nocturnal surveys uncovered seahorse densities 259% higher than daytime transects on average. Sex ratios were consistently male-biased, and the frequency of animals from different reproductive categories varied significantly by time of day, with gravid males observed around the clock but females and nongravid males observed more often at night. Spatial and seasonal recruitment was detected for the first time in this species, with an increase in juveniles detected in the shallow ends of transects during dry season surveys. Juvenile recruitment is poorly understood across syngnathid fishes, so the detection of early recruits at night has broad implications for this fish family. Seahorses from all reproductive categories were perched significantly higher in the water column during the night regardless of their depth or season. Predator densities followed a similar pattern with higher densities observed at night, indicating that elevated nocturnal perch height may be a response to predator presence. However, the selective agents driving these nocturnal behaviors have yet to be identified. Considering H. erectus is listed on the IUCN Red List as "Vulnerable," the increase in nocturnal population size and the detection of juveniles has crucial implications for understanding their ecology, recruitment, and conservation.
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Affiliation(s)
| | - Emily Rose
- The University of TampaTampaFloridaUSA
- Present address:
Department of BiologyValdosta State UniversityValdostaGeorgiaUSA
| | | | - Duncan A. O'Brien
- The Center for Ocean Research and EducationGregorytown, EleutheraThe Bahamas
- Present address:
School of Biological SciencesUniversity of BristolBristolUK
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Cabral AE, Ricardo F, Patinha C, da Silva EF, Correia M, Palma J, Planas M, Calado R. Successful Use of Geochemical Tools to Trace the Geographic Origin of Long-Snouted Seahorse Hippocampus guttulatus Raised in Captivity. Animals (Basel) 2021; 11:ani11061534. [PMID: 34070251 PMCID: PMC8225026 DOI: 10.3390/ani11061534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/14/2021] [Accepted: 05/20/2021] [Indexed: 11/21/2022] Open
Abstract
Simple Summary Seahorses (Hippocampus spp.) are currently exposed to a multitude of anthropogenic pressures worldwide. The illegal, unreported, and unregulated (IUU) fisheries and trade of these flagship species undermine the efforts to manage and protect their wild populations. Here we aim to validate a forensic tool to identify the geographic origin of seahorses and contribute to the ongoing fight against the illegal capture and trade of these organisms. The elemental fingerprints of long-snouted seahorse (Hippocampus guttulatus) bony structures, including the subdermal bony plates that cover their body, revealed that they can be successfully employed to confirm their geographic origin. The results of this first study using seahorses raised in captivity indicate that this tool may also allow to discriminate between different populations of wild specimens and enhance the traceability of traded specimens. Abstract The global market of dried seahorses mainly supplies Traditional Chinese Medicine and still relies on blurry trade chains that often cover less sustainable practices targeting these pricey and endangered fish. As such, reliable tools that allow the enforcement of traceability, namely to confirm the geographic origin of traded seahorses, are urgently needed. The present study evaluated the use of elemental fingerprints (EF) in the bony structures of long-snouted seahorses Hippocampus guttulatus raised in captivity in two different locations (southern Portugal and Northern Spain) to discriminate their geographic origin. The EF of different body parts of H. guttulatus were also evaluated as potential proxies for the EF of the whole body, in order to allow the analysis of damaged specimens and avoid the use of whole specimens for analysis. The contrasting EF of H. guttulatus raised in the two locations allowed their reliable discrimination. Although no single body part exactly mimicked the EF of the whole body, seahorse trunks, as well as damaged specimens, could still be correctly allocated to their geographic origin. This promising forensic approach to discriminate the geographic origin of seahorses raised in captivity should now be validated for wild conspecifics originating from different locations, as well as for other species within genus Hippocampus.
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Affiliation(s)
- Ana Elisa Cabral
- ECOMARE, CESAM-Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Santiago University Campus, 3810-193 Aveiro, Portugal; (A.E.C.); (F.R.)
| | - Fernando Ricardo
- ECOMARE, CESAM-Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Santiago University Campus, 3810-193 Aveiro, Portugal; (A.E.C.); (F.R.)
| | - Carla Patinha
- GEOBIOTEC—Department of Geosciences, University of Aveiro, Santiago University Campus, 3810-193 Aveiro, Portugal; (C.P.); (E.F.d.S.)
| | - Eduardo Ferreira da Silva
- GEOBIOTEC—Department of Geosciences, University of Aveiro, Santiago University Campus, 3810-193 Aveiro, Portugal; (C.P.); (E.F.d.S.)
| | - Miguel Correia
- CCMAR Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal; (M.C.); (J.P.)
| | - Jorge Palma
- CCMAR Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal; (M.C.); (J.P.)
| | - Miquel Planas
- Department of Ecology and Marine Resources, IIM-CSIC-Instituto de Investigaciones Marinas (IIM), 36208 Vigo, Spain;
| | - Ricardo Calado
- ECOMARE, CESAM-Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Santiago University Campus, 3810-193 Aveiro, Portugal; (A.E.C.); (F.R.)
- Correspondence: ; Tel.: +351-2343-70779
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Schwarz Junior R, Franco ACNP, Ribeiro ADS, Martins MA, Soeth M, Cardoso OR, Spach HL. Ecological and growth patterns of the longsnout seahorse Hippocampus reidi inferred by mark-recapture techniques in a tropical estuary. BIOTA NEOTROPICA 2021. [DOI: 10.1590/1676-0611-bn-2020-1130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract: The population structure of the longsnout seahorse Hippocampus reidi (Ginsburg 1933) was evaluated in an estuarine system in northeastern Brazil. A total of 425 captures were performed in the Vaza-Barris estuary and 232 individuals were marked with Visible Implant Fluorescent Elastomers. The population was estimated to be composed of 428 fish. The von Bertalanffy growth curve shows a steeper growth during the first months of life, up to about 17 months, and stabilization after 16 cm and 27 months of age. The hereby study indicates that the Vaza-Barris estuary is home to resident populations of longsnout seahorses. Moreover, these populations use mangrove roots as the main substrate for attachment and present well-defined ecological characteristics, such as habitat fidelity and highly structured social organization.
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Affiliation(s)
| | | | | | | | - Marcelo Soeth
- Universidade Federal do Paraná, Brasil; Universidade Federal do Paraná, Brasil
| | | | - Henry Louis Spach
- Universidade Federal do Paraná, Brasil; Universidade Federal do Paraná, Brasil; Universidade Federal do Paraná, Brasil
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Claassens L, Harasti D. Life history and population dynamics of an endangered seahorse (Hippocampus capensis) within an artificial habitat. JOURNAL OF FISH BIOLOGY 2020; 97:974-986. [PMID: 32621517 DOI: 10.1111/jfb.14452] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 06/18/2020] [Accepted: 07/02/2020] [Indexed: 06/11/2023]
Abstract
Species-specific life-history information is critical for successful conservation, particularly in establishing an accurate baseline status. Obtaining such information is challenging for most species, but in particular for rare and threatened marine species. To facilitate future conservation of the endangered Knysna seahorse (Hippocampus capensis) this study aimed to determine important life-history information for this species. Visible implant fluorescent elastomer (VIFE) tags were used to mark 78 seahorses within a residential marina estate in the Knysna estuary, South Africa, in February 2018. Using a mark-resight approach, the size and movement patterns of the population and growth rate of seahorses were determined over a 14-month period. The closed population estimate for H. capensis, within Thesen Islands Marina, was estimated to be 134 (118-152 95% C.I.) in February 2018 compared to only 72 (48-108 95% C.I.) in February 2019. The species showed rapid initial growth with males and females having similar rates of growth based on the specialised von Bertalanffy growth function model. The importance of Reno mattresses as a habitat for H. capensis was confirmed based on the high abundance and site fidelity of the population, which emphasises the conservation potential of heavily modified environments for threatened seahorse species. The use of VIFE tags was deemed effective in studying this endangered seahorse and allowed the collection of important information for this species which can be used in future Red List assessments and conservation actions.
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Affiliation(s)
- Louw Claassens
- Department of Zoology & Entomology, Rhodes University, Grahamstown, Republic of South Africa
- Knysna Basin Project, Knysna, Republic of South Africa
| | - David Harasti
- Fisheries Research, NSW Department of Primary Industries, Taylors Beach, New South Wales, Australia
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Rose E, Simmonds M, Hayashida-Boyles AL, Masonjones HD. Seasonal and spatial variation in the reproductive biology of the dwarf seahorse Hippocampus zosterae. JOURNAL OF FISH BIOLOGY 2019; 95:357-366. [PMID: 30968411 DOI: 10.1111/jfb.13975] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Accepted: 04/08/2019] [Indexed: 06/09/2023]
Abstract
Factors associated with the reproductive ecology of the dwarf seahorse Hippocampus zosterae were investigated. Fish from a Tampa Bay (FL, USA) seagrass ecosystem were collected, photographed and returned to the wild, with photos analysed to determine patterns of body size, density, sex ratio and reproductive state across site and season to understand the population dynamics of H. zosterae over time. Animal density did not vary significantly with site and season, indicating there is little evidence of seasonal migration in this species. Densities reported in this study were higher than the mean density for all seahorse species Hippocampus spp. There was no sexual dimorphism in body length and both sexes reached sexual maturity at the same size. The ratio of gravid to non-gravid males was found to shift by season but not by site, with breeding detected year-round in this population compared with populations further north in their range. Peak breeding (70% gravid males) was observed in the late summer-autumn (August-October) in the site furthest from shore. The largest fish for both sexes were recorded during the summer and autumn months in the mid-shore, deepest site. Sex ratio shifted by site with even sex ratios near the shore but significantly female-biased sex ratios detected at sites near open water. Lastly, an increase in marking dates with decreased time intervals between collections did not yield a higher recapture rate, compared with sampling in 2010. However, the Tampa Bay population of dwarf seahorses demonstrated stable densities across 3 years with year-round breeding, indicating that it is a robust population worthy of long-term monitoring for conservation efforts.
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Affiliation(s)
- Emily Rose
- Biology Department, The University of Tampa, Tampa, Florida, USA
| | | | - Alana L Hayashida-Boyles
- Biology Department, The University of Tampa, Tampa, Florida, USA
- College of Biological, Marine & Environmental Sciences, James Cook University, Douglas, Queensland, Australia
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Woodall LC, Otero-Ferrer F, Correia M, Curtis JMR, Garrick-Maidment N, Shaw PW, Koldewey HJ. A synthesis of European seahorse taxonomy, population structure, and habitat use as a basis for assessment, monitoring and conservation. MARINE BIOLOGY 2017; 165:19. [PMID: 29238097 PMCID: PMC5717113 DOI: 10.1007/s00227-017-3274-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 11/22/2017] [Indexed: 06/07/2023]
Abstract
Accurate taxonomy, population demography, and habitat descriptors inform species threat assessments and the design of effective conservation measures. Here we combine published studies with new genetic, morphological and habitat data that were collected from seahorse populations located along the European and North African coastlines to help inform management decisions for European seahorses. This study confirms the presence of only two native seahorse species (Hippocampus guttulatus and H. hippocampus) across Europe, with sporadic occurrence of non-native seahorse species in European waters. For the two native species, our findings demonstrate that highly variable morphological characteristics, such as size and presence or number of cirri, are unreliable for distinguishing species. Both species exhibit sex dimorphism with females being significantly larger. Across its range, H. guttulatus were larger and found at higher densities in cooler waters, and individuals in the Black Sea were significantly smaller than in other populations. H. hippocampus were significantly larger in Senegal. Hippocampus guttulatus tends to have higher density populations than H. hippocampus when they occur sympatrically. Although these species are often associated with seagrass beds, data show both species inhabit a wide variety of shallow habitats and use a mixture of holdfasts. We suggest an international mosaic of protected areas focused on multiple habitat types as the first step to successful assessment, monitoring and conservation management of these Data Deficient species.
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Affiliation(s)
- Lucy C. Woodall
- Department of Zoology, University of Oxford, Oxford, UK
- Project Seahorse, Zoological Society of London, Regent’s Park, London, UK
| | - Francisco Otero-Ferrer
- Grupo en Biodiversidad y Conservación, IU-ECOAQUA, Universidad de Las Palmas de Gran Canaria, Crta. Taliarte s/n, 35214 Telde, Spain
| | - Miguel Correia
- Project Seahorse, Zoological Society of London, Regent’s Park, London, UK
- CCMar, Universidade do Algarve, F. C. T., Edificio 7, Campus de Gambelas, 8005-139 Faro, Portugal
| | - Janelle M. R. Curtis
- Pacific Biological Station, Fisheries and Oceans Canada, 3190 Hammond Bay Road, Nanaimo, BC Canada
| | | | - Paul W. Shaw
- Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, UK
| | - Heather J. Koldewey
- Project Seahorse, Zoological Society of London, Regent’s Park, London, UK
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK
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