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1.
Biology (Basel) ; 12(7)2023 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-37508405

RESUMEN

Sampling efforts on the Saya de Malha Bank (part of the Mascarene Plateau, western Indian Ocean) unveiled three unusual small juvenile angel shark specimens, that were a much paler color than the only known western Indian Ocean species, Squatina africana Regan, 1908. However, it took many years before further specimens, including adults of both sexes, and tissue samples were collected. The present manuscript contains a redescription of S. africana based on the holotype and additional material, as well as the formal description of the new species of Squatina. All specimens of the new species, hereafter referred to as Squatina leae sp. nov., were collected in the western Indian Ocean off southwestern India and on the Mascarene Plateau at depths of 100-500 m. The new species differs from S. africana in a number of characteristics including its coloration when fresh, smaller size at birth, size at maturity, and adult size, genetic composition, and distribution. Taxonomic characteristics include differences in the morphology of the pectoral skeleton and posterior nasal flap, denticle arrangement and morphology, vertebral counts, trunk width, pectoral-pelvic space, and clasper size. A key to the species of Squatina in the Indian Ocean is provided.

2.
Jamba ; 14(1): 1285, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36483005

RESUMEN

Blue Ventures (BV) works holistically with communities in Madagascar, developing transformative approaches to catalyse and sustain locally led marine conservation. In response to the coronavirus disease 2019 (COVID-19) pandemic, BV's priority was to safeguard the immediate wellbeing and livelihoods of as many communities as possible, recognising that livelihoods are integral to broader well-being. This article describes in detail BV's health response and the perceptions of BV's Madagascar team regarding the successes and challenges of this effort. As a result of the combined efforts of BV teams across Madagascar and in the United Kingdom, the existing healthcare services at BV's sites were maintained, and messages about recognising and dealing with COVID-19 and the importance of vaccination were conveyed to communities that might otherwise not have received comprehensive information. Data were also collected on suspected cases in areas where testing was not available, and outbreaks of suspected COVID-19 cases were managed. Because BV's teams are embedded within the communities where they work, they maintain strong relationships with communities and conveyed important messages around reducing the spread of COVID-19, not only via activities in response to the pandemic but also through activities for other programmes such as fisheries and livelihoods. Blue Ventures' holistic approach ensured that the organisation had a multidimensional understanding of the impacts of the pandemic on communities, facilitating the development of more relevant messaging that considered both safety and the need for continued income-generating activities. Staff felt that an effective public health response was facilitated by strong in-country partnerships and BV's long-standing presence in communities. Contribution: The challenges in responding to the pandemic and in implementing and maintaining effective behaviour change are discussed. Although not an objective study of the effectiveness of the response or a comparison with other approaches, the lessons learned from this process are shared in the hope that they may inform responses to future shocks in low-income countries.

3.
Sci Adv ; 7(7)2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33568471

RESUMEN

Extinctions on land are often inferred from sparse sightings over time, but this technique is ill-suited for wide-ranging species. We develop a space-for-time approach to track the spatial contraction and drivers of decline of sawfishes. These iconic and endangered shark-like rays were once found in warm, coastal waters of 90 nations and are now presumed extinct in more than half (n = 46). Using dynamic geography theory, we predict that sawfishes are gone from at least nine additional nations. Overfishing and habitat loss have reduced spatial occupancy, leading to local extinctions in 55 of the 90 nations, which equates to 58.7% of their historical distribution. Retention bans and habitat protections are urgently necessary to secure a future for sawfishes and similar species.

4.
PLoS One ; 15(3): e0228791, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32187191

RESUMEN

Recent sampling efforts in Madagascar and Zanzibar, as well as examinations of six-gilled sawsharks in several museum collections provided evidence for a complex of species within Pliotrema warreni Regan. The present manuscript contains a redescription of P. warreni involving the syntypes and additional material, as well as formal descriptions of two new species of Pliotrema Regan. All specimens of both new species were found in the western Indian Ocean. Individuals of the first new species, hereafter referred to as P. kajae sp. nov., were identified originating from Madagascar and the Mascarene Ridge. Specimens of the second new species, hereafter referred to as P. annae sp. nov., were only found off Zanzibar. Pliotrema kajae sp. nov. appears to inhabit upper insular slopes and submarine ridges at depths of 214-320 m, P. annae sp. nov. so far is only known from shallow waters (20-35 m). Both new species differ from P. warreni in a number of characteristics including the known distribution range and fresh coloration. Taxonomical differences include barbels that are situated approximately half way from rostral tip to mouth, with prebarbel length equidistant from barbel origin to symphysis of the upper jaw in P. kajae sp. nov. and P. annae sp. nov. (vs. about two thirds way from rostral tip to mouth, with prebarbel length about twice the distance from barbel origin to symphysis of upper jaw in P. warreni) and rostra that are clearly and slightly constricted between barbel origin and nostrils, respectively (vs. rostrum not constricted). Pliotrema kajae sp. nov. differs from P. annae sp. nov. in a longer snout, more numerous large lateral rostral teeth and upper jaw tooth rows, jaw teeth with (vs. without) sharp basal folds, and coloration, particularly pale to light brown (vs. medium to dark brown) dorsal coloration with (vs. without) two indistinct yellowish stripes. A revised diagnosis of Pliotrema and a key to the species are provided.


Asunto(s)
Elasmobranquios/clasificación , Maxilares/anatomía & histología , Diente/anatomía & histología , Distribución Animal , Animales , Ecosistema , Elasmobranquios/anatomía & histología , Femenino , Océano Índico , Madagascar , Masculino , Filogenia , Dinámica Poblacional , Tanzanía
5.
PeerJ ; 5: e2950, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28168114

RESUMEN

Sawfishes (Pristidae) were formerly abundant in the western Indian Ocean, but current data on sawfish presence and distribution are lacking for most of the region. This paper summarises historical records of sawfishes in Mozambican waters and presents the findings of the first assessment of the presence and status of sawfishes in Mozambique. A countrywide baseline assessment was undertaken between May and July 2014, using interviews with artisanal, semi-industrial and industrial fishers, fish traders and fisheries monitoring staff as the primary source of information on sawfish distribution, recent catches, socio-economic value and cultural importance. Additional interviews were conducted via email or telephone with individuals running sport fishing operations or who otherwise had considerable experience interacting with the fishing sectors or the marine environment in Mozambique. Where encountered, sawfish rostra were photographed and a series of measurements and associated data were collected. In total, 200 questionnaire surveys and seven interviews with recreational fishing and dive operators were conducted, and 19 rostra were documented from museum archives and private collections, belonging to two sawfish species, the Largetooth Sawfish (Pristis pristis) and Green Sawfish (P. zijsron). The most recent captures of sawfishes were reported to have occurred in 2014. Two key sites were identified where both recent encounters were reported and numerous Largetooth Sawfish rostra were documented. Gill nets were the fishing gear most commonly attributed to sawfish catches. Sawfishes did not hold any cultural importance in Mozambique, but they have at least some socio-economic importance to artisanal fishers, primarily through the sale of their fins. The meat did not appear to be held in high regard and was usually consumed locally. Sampling and further research is now required to confirm the presence of sawfishes and to assess the primary threats to sawfishes in those areas. At one site where a number of rostra were present and where fishers stated that they still catch sawfish, gill nets are being provided to fishers as an alternative to beach seining. This may have a serious impact on the local sawfish population and more broadly for other elasmobranchs in the area. Immediate action is required to develop a landings monitoring programme in this and other key habitats, and to encourage fishers to release sawfishes alive.

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