[MARMAM] New publications on abnormalities in free-ranging cetaceans
filalves at rocketmail.com
Fri Nov 24 01:52:17 PST 2017
we are pleased to announce three recent Notes on abnormalities in free-ranging cetaceans:
1) Alves F, JR Towers, RW Baird, G Bearzi, S Bonizzoni, R Ferreira, Z Halicka, A Alessandrini, AH Kopelman, C Yzoard, MH Rasmussen, CG Bertulli, E Jourdain, A Gullan, D Rocha, K Hupman, M-T Mrusczok, FIP Samarra, S Magalhães, CR Weir, JKB Ford, A Dinis (2017) The incidence of bent dorsal fins in free-ranging cetaceans. Journal of Anatomy, doi: 10.1111/joa.12729A
Laterally bent dorsal fins are rarely observed in free-ranging populations of cetaceans, contrary to captivity, where most killer whale Orcinus orca adult males have laterally collapsed fins. This topic has been poorly explored, and data/information on its occurrence and possible causes are limited. The present study: (i) undertakes a review of the available information on bent dorsal fins in free-ranging cetaceans, and updates it with new records, (ii) reports on the proportion of bent fins in different study populations, and (iii) discusses possible causes. An empirical approach based on bibliographic research and compilation of 52 new records collected worldwide resulted in a total of 17 species of cetaceans displaying bent dorsal fins. The species with the highest number of records (64%) and from most locations was O. orca. On average, individuals with bent dorsal fins represent < 1% of their populations, with the exception of false killer whales Pseudorca crassidens and O. orca. While line injuries associated with fisheries interactions may be the main cause for P. crassidens, and the vulnerability to health issues caused by the evolutionary enlargement of the fin may be the cause for O. orca adult males, factors contributing to this abnormality for other species are still unclear. The occurrence of bent dorsals could be influenced by a set of variables rather than by a single factor but, irrespective of the cause, it is suggested that it does not directly affect the animals' survivorship. While still rare in nature, this incident is more common (at least 101 known cases) and widespread (geographically and in species diversity) than hypothesized, and is not confined only to animals in captive environments. Investigation into the occurrence of bent fins may be an interesting avenue of research.
Available at: http://onlinelibrary.wiley.com/doi/10.1111/joa.12729/abstract
2) Alves F, R Ferreira, L Dias, C Nicolau, D Sousa, C Moura, C Gomes, A Dinis (2017) Rare records of hypo- and hyper-pigmented individuals in two delphinid species off Madeira island. Hystrix, doi:10.4404/hystrix-28.1-11888
AbstractSightings of anomalously all-white (leucistic) or all-black (melanistic) individuals are rare innature, with information on hypo- and hyper-pigmented short-beaked common dolphins (Delphinusdelphis) and Atlantic spotted dolphins (Stenella frontalis) being scarce in the literature. Thisstudy describes seven sightings of anomalously pigmented D. delphis and S. frontalis recorded offMadeira Island between 2014 and 2016. This includes: i) four records of a dark-pigmented D.delphis that lacked the distinctive hourglass colour (yellow) pattern, ii) two records of an all-whiteD. delphis, and iii) one record of an all-white S. frontalis. All records consisted of full-sized animalsand were observed displaying the same behaviour as the other individuals in the same group,with no other delphinid species in the vicinities. The all-white individuals had a normal (dark)eye colouration, which indicated that the animals were not true albinos, but rather leucistic individuals.Despite inherent limitations of this condition, the adults observed in this study confirmedthe potential longevity of these anomalously pigmented individuals in the wild. Similar reports asof those described here may provide a framework to better understand these animals. This studyfurther highlights the value of sharing photographs via social media forums (e.g. Facebook).
Available at: http://www.italian-journal-of-mammalogy.it/article/view/11888/pdf (OPEN ACCESS)
3) Dinis A, RW Baird, SD Mahaffy, V Martín, F. Alves (2017) Beaked whales with rostrum deformities: Implications for survival and reproduction. Marine Mammal Science 33(3), 946-954. doi: 10.1111/mms.12406
Available at: http://onlinelibrary.wiley.com/doi/10.1111/mms.12406/abstract
Feel free to contact me for pdf requests, preferably to filipe.alves at ciimarmadeira.orgRegards,
Oceanic Observatory of Madeira / ARDITI
Caminho da Penteada, Tecnopolo,
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