14 research outputs found
Metal concentrations in selected tissues and main prey species of the annulated sea snake (Hydrophis cyanocinctus) in the Hara Protected Area, northeastern coast of the Persian Gulf, Iran.
This study is the first detailed ecotoxicological study of the annulated sea snake, Hydrophis cyanocinctus. Concentrations of lead, cadmium, nickel and vanadium were evaluated in muscle, liver, kidney, skin and blood of the annulated sea snake (H. cyanocinctus) and in the whole bodies of its main prey species (Periophthalmus waltoni and Boleophthalmus dussumieri) in the Hara Protected Area, the Persian Gulf. The mean concentrations of lead and vanadium were highest in the kidney, which identified the kidney as a target organ for metals in sea snakes as it is in other reptilian groups. Mean concentrations of cadmium and nickel were highest in the liver and skin, respectively. Mean cadmium concentrations were significantly higher in the liver compared to prey species, which indicated that prey items may be a source of cadmium for the annulated sea snake in the study area. Data presented here may be considered as a baseline for further ecotoxicological studies in sea snakes
Evaluating the drivers of Indo-Pacific biodiversity: speciation and dispersal of sea snakes (Elapidae: Hydrophiinae)
Aim: There are several competing hypotheses to explain the high species richness of the Indo-Australian Archipelago (IAA) marine biodiversity hotspot centred within Southeast (SE) Asia. We use phylogenetic methods to provide a novel perspective on this problem using viviparous sea snakes, a group with high species richness in the IAA that is highly distinct from other taxa previously studied, both phylogenetically (Reptilia, Amniota) and biologically (e.g. viviparity and direct development). Location: Indian Ocean and the West Pacific. Methods: We used likelihood and Bayesian methods to reconstruct a multi-locus time-calibrated phylogeny for c. 70% of viviparous sea snake species, many sampled from multiple localities in Australasia, Southeast Asia and the Indian Ocean. We then compared rates and temporal concordance of inferred vicariance and dispersal events between marine basins using several approaches including new Bayesian analyses that allow for clade-specific and event-specific dispersal rates. Results: Phylogenetic analyses and novel Bayesian biogeographical reconstructions indicate that viviparous sea snakes underwent rapid speciation after colonizing SE Asia c. 3 million years ago. Most of the SE Asian sea snake diversity is the result of in situ speciation, most consistent with the ‘centre of origin’ and ‘centre of refuge’ models for biodiversity hotspots. There is also speciation at the periphery, or entirely outside SE Asia; however, contrary to predictions of the ‘accumulation’ and ‘overlap’ models, these new outlying taxa do not preferentially disperse back into SE Asia. Instead, lineages are equally likely to disperse either into or away from SE Asia. Main conclusion: The high diversity of sea snakes in SE Asia (and hence the IAA) is mostly explained by in situ speciation rather than accumulation or overlap. Most speciation events are contemporaneous with sea level changes that generated and dissolved barriers between marine basins during the last 2.5 million years.Kanishka D.B. Ukuwela, Michael S.Y. Lee, Arne R. Rasmussen, Anslem de Silva, Mumpuni, Bryan G. Fry, Parviz Ghezellou, Mohsen Rezaie-Atagholipour, and Kate L. Sander
Epibiont Assemblages on Nesting Hawksbill Turtles Show Site-Specificity in the Persian Gulf
Sea turtle epibionts can provide insights into the hosts' habitat use. However, at present, there is a lack of information on sea turtle epibiont communities in many locations worldwide. Here, we describe the epibiont communities of 46 hawksbill turtles (Eretmochelys imbricata) in the Persian Gulf. Specifically, we sampled 28 turtles from the Dayyer-Nakhiloo National Park (DNNP) in the northern Gulf and 18 turtles from Shibderaz beach in the Strait of Hormuz. A total of 54 macro, meio, and micro-epibiont taxa were identified, including 46 taxa from Shibderaz and 29 taxa from DNNP. The barnacles Chelonibia testudinaria and Platylepas hexastylos, as well as harpacticoid copepods and Rotaliid foraminifers, had the highest frequency of occurrence found on almost all turtle individuals. Harpacticoids were the most abundant epizoic taxa (19.55 ± 3.9 ind. per 9 cm2) followed by forams (Quinqueloculina spp.: 6.25 ± 1.5 ind. per 9 cm2 and Rotaliids: 6.02 ± 1.3 ind. per 9 cm2). Our results showed significant differences between the study sites in the composition of micro and macro-epibiont communities found on hawksbill turtles. We speculate that the differences in epibiont communities were largely influenced by local environmental conditions
Sea snakes (Elapidae, Hydrophiinae) in their westernmost extent: an updated and illustrated checklist and key to the species in the Persian Gulf and Gulf of Oman
The Persian Gulf is known as the westernmost distribution limit for sea snakes, except for Hydrophis platurus (Linnaeus, 1766) that reaches southeastern Africa. Previous identification guides for sea snakes of the Persian Gulf and its adjacent waters in the Gulf of Oman were based on old data and confined mostly to written descriptions. Therefore, a series of field surveys were carried out in 2013 and 2014 through Iranian coastal waters of both gulfs to provide a comprehensive sampling of sea snakes in the area. This paper presents an illustrated and updated checklist and identification tool for sea snakes in the Persian Gulf and Gulf of Oman, which are based on new material and a review of the literature. This checklist includes ten species of marine hydrophiines, of which one, Microcephalophis cantoris (Günther, 1864), is a new record for the area. All specimens examined herein are deposited and available at the Zoological Museum of Shahid Bahonar University of Kerman, Kerman province, Iran
Genetic diversity among sea snakes of the genus Hydrophis (Elapidae, Reptilia) in the Persian Gulf and Gulf of Oman
The Persian Gulf and Gulf of Oman are two important marine ecosystems in southern Iran with rich biodiversity. Sea snakes of the genus Hydrophis are important components of the animal diversity in this area. Ten species of the genus Hydrophis have been distinguished in the region and their genetic structure was compared with other populations in south and southeast Asia. We found that five species (including H. platurus, H. cyanocinctus, H. spiralis, H. schistosus and H. gracilis, H. lapemiodes) show high genetic similarity with conspecific populations in the Indian Ocean and Australia. Hydrophis curtus from southern Iran shows a high level of differentiation from other populations in Sri Lanka and Australia. Hydrophis curtus in our study shows variation and the Iranian samples of the species of 0.6% and 6% genetic distance from other populations in Sri Lanka for 16S and COI gene fragments, respectively. This means the variability between Iranian and southeast Asia populations may reveal new genetic lineages and the need of further morphological evaluations to re-evaluate their taxonomic position
Genetic diversity among sea snakes of the genus Hydrophis (Elapidae, Reptilia) in the Persian Gulf and Gulf of Oman
Sea snakes of the genus Hydrophis are important components of animal diversity in Iranian waters of the Persian Gulf and Gulf of Oman. Ten species of Hydrophis have been identified from the these waters and, in this study, genetic structure of seven species was compared with other populations in the eastern Indian Ocean and the West Pacific. We found that six species (H. platurus, H. cyanocinctus, H. spiralis, H. schistosus, H. gracilis, and H. lapemiodes) show high genetic similarity with conspecific populations in the Indian Ocean and Australia. However, H. curtus from southern Iran shows a high level of genetic differentiation from conspecific populations in Sri Lanka and Indonesia (0.6% and 6% genetic distance from Sri Lankan samples for 16S and COI gene fragments, respectively). Variation between Iranian and Southeast Asian populations may reflect new genetic lineages and suggest the need of further morphological evaluations to re-evaluate their taxonomic position
Evaluating the drivers of Indo-Pacific biodiversity: speciation and dispersal of sea snakes (Elapidae: hydrophiinae)
Aim: There are several competing hypotheses to explain the high species richness of the Indo-Australian Archipelago (IAA) marine biodiversity hotspot centred within Southeast (SE) Asia. We use phylogenetic methods to provide a novel perspective on this problem using viviparous sea snakes, a group with high species richness in the IAA that is highly distinct from other taxa previously studied, both phylogenetically (Reptilia, Amniota) and biologically (e.g.viviparity and direct development). Location: Indian Ocean and the West Pacific. Methods: We used likelihood and Bayesian methods to reconstruct a multi-locus time-calibrated phylogeny for c.70% of viviparous sea snake species, many sampled from multiple localities in Australasia, Southeast Asia and the Indian Ocean. We then compared rates and temporal concordance of inferred vicariance and dispersal events between marine basins using several approaches including new Bayesian analyses that allow for clade-specific and event-specific dispersal rates. Results: Phylogenetic analyses and novel Bayesian biogeographical reconstructions indicate that viviparous sea snakes underwent rapid speciation after colonizing SE Asia c.3 million years ago. Most of the SE Asian sea snake diversity is the result of insitu speciation, most consistent with the 'centre of origin' and 'centre of refuge' models for biodiversity hotspots. There is also speciation at the periphery, or entirely outside SE Asia; however, contrary to predictions of the 'accumulation' and 'overlap' models, these new outlying taxa do not preferentially disperse back into SE Asia. Instead, lineages are equally likely to disperse either into or away from SE Asia. Main conclusion: The high diversity of sea snakes in SE Asia (and hence the IAA) is mostly explained by insitu speciation rather than accumulation or overlap. Most speciation events are contemporaneous with sea level changes that generated and dissolved barriers between marine basins during the last 2.5 million years
Figure 9 from: Rezaie-Atagholipour M, Ghezellou P, Hesni MA, Dakhteh SMH, Ahmadian H, Vidal N (2016) Sea snakes (Elapidae, Hydrophiinae) in their westernmost extent: an updated and illustrated checklist and key to the species in the Persian Gulf and Gulf of Oman. ZooKeys 622: 129-164. https://doi.org/10.3897/zookeys.622.9939
Contribution of citizen science to improve knowledge on marine biodiversity in the Gulf Region
Monitoring marine biodiversity is costly and practical solutions have to be implemented to identify species and their preferred habitats, particularly in this era of rapid global change. Citizen science has proven to be effective and with high potential for monitoring efforts, and has been extensively applied to biodiversity. We have used the citizen science approach to engage the general public and stakeholders to contribute improving the current knowledge of sea snake biodiversity in Qatar and the Gulf Region. Logistic regression analysis using demographic data from interview surveys conducted in Qatar has indicated that the people having seen more sea snakes are older than 30 years and are Qatari citizens and/or fishermen from India. Of the ten species of sea snakes listed in the literature to be present in the Gulf Region, most of them have been reported for Qatar, Bahrain, United Arab Emirates and Saudi Arabia. However, the number of species present is often assumed based on their occurrence within the Arabian Gulf rather than on actual captures and appropriate identification. The creation of marine reference biological scientific collections to properly identify the species and make accurate biodiversity inventories is an urgent priority for the countries in the Gulf region. To this end, contributions by stakeholders and the general public for this study have proven to be very useful. However a larger networking with local and international scientists and stakeholders is still needed to adequately survey the country''s current biodiversity, identify research priorities and eventually provide the scientific input needed to assist biodiversity management related to renewable resource management and marine conservation in the Arabian Gulf Region