Life history of the vaquita, Phocoena sinus (Phocoenidae, Cetacea)
The vaquita, Phocoena sinus , is the most endangered marine cetacean primarily due to incidental mortality in fishing nets. We examined a sample of 56 vaquitas to study the life history of this poorly known species. The age structure was bimodal, with 62% of the specimens from 0‐2 years and 31% from...
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Format: | Article in Journal/Newspaper |
Language: | English |
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Wiley
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Online Access: | http://dx.doi.org/10.1111/j.1469-7998.1996.tb05450.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1469-7998.1996.tb05450.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1996.tb05450.x https://zslpublications.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1996.tb05450.x |
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crwiley:10.1111/j.1469-7998.1996.tb05450.x 2024-09-09T19:43:49+00:00 Life history of the vaquita, Phocoena sinus (Phocoenidae, Cetacea) Hohn, A. A. Read, A. J. Fernandez, S. Vidal, O. Findley, L. T. 1996 http://dx.doi.org/10.1111/j.1469-7998.1996.tb05450.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1469-7998.1996.tb05450.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1996.tb05450.x https://zslpublications.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1996.tb05450.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Journal of Zoology volume 239, issue 2, page 235-251 ISSN 0952-8369 1469-7998 journal-article 1996 crwiley https://doi.org/10.1111/j.1469-7998.1996.tb05450.x 2024-08-20T04:17:40Z The vaquita, Phocoena sinus , is the most endangered marine cetacean primarily due to incidental mortality in fishing nets. We examined a sample of 56 vaquitas to study the life history of this poorly known species. The age structure was bimodal, with 62% of the specimens from 0‐2 years and 31% from 11‐16 years; the sample contained no specimens from ages 3‐6 years. The oldest individual was estimated to be 21 years old. All specimens less than three years old were sexually immature and all greater than six years old were mature. The asymptotic length of females (140.6 cm) was significantly greater than that of males (134.9 cm), although no difference was detected in asymptotic girth or body mass. Reproduction is synchronous; births occurred from late February to early April and maximum testes activity occurred from mid‐March through to at least mid‐April. Our observations from this small sample suggest that the calving interval is greater than one year. The sample was too small for many quantitative analyses, although it appears that lifespan, patterns of growth, age at sexual maturation, seasonal reproduction, and large testis size are similar to the harbour porpoise, P. phocoena , in a highly exploited and well‐studied population from the Bay of Fundy. A significant difference, however, is that harbour porpoise females give birth annually, indicating that the rate of increase in the vaquita population is likely to be lower than that in the harbour porpoise. Without immediate cessation of fishing pressure, this fragile population will collapse, resulting in extinction of the vaquita. Article in Journal/Newspaper Harbour porpoise Wiley Online Library Journal of Zoology 239 2 235 251 |
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Open Polar |
collection |
Wiley Online Library |
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crwiley |
language |
English |
description |
The vaquita, Phocoena sinus , is the most endangered marine cetacean primarily due to incidental mortality in fishing nets. We examined a sample of 56 vaquitas to study the life history of this poorly known species. The age structure was bimodal, with 62% of the specimens from 0‐2 years and 31% from 11‐16 years; the sample contained no specimens from ages 3‐6 years. The oldest individual was estimated to be 21 years old. All specimens less than three years old were sexually immature and all greater than six years old were mature. The asymptotic length of females (140.6 cm) was significantly greater than that of males (134.9 cm), although no difference was detected in asymptotic girth or body mass. Reproduction is synchronous; births occurred from late February to early April and maximum testes activity occurred from mid‐March through to at least mid‐April. Our observations from this small sample suggest that the calving interval is greater than one year. The sample was too small for many quantitative analyses, although it appears that lifespan, patterns of growth, age at sexual maturation, seasonal reproduction, and large testis size are similar to the harbour porpoise, P. phocoena , in a highly exploited and well‐studied population from the Bay of Fundy. A significant difference, however, is that harbour porpoise females give birth annually, indicating that the rate of increase in the vaquita population is likely to be lower than that in the harbour porpoise. Without immediate cessation of fishing pressure, this fragile population will collapse, resulting in extinction of the vaquita. |
format |
Article in Journal/Newspaper |
author |
Hohn, A. A. Read, A. J. Fernandez, S. Vidal, O. Findley, L. T. |
spellingShingle |
Hohn, A. A. Read, A. J. Fernandez, S. Vidal, O. Findley, L. T. Life history of the vaquita, Phocoena sinus (Phocoenidae, Cetacea) |
author_facet |
Hohn, A. A. Read, A. J. Fernandez, S. Vidal, O. Findley, L. T. |
author_sort |
Hohn, A. A. |
title |
Life history of the vaquita, Phocoena sinus (Phocoenidae, Cetacea) |
title_short |
Life history of the vaquita, Phocoena sinus (Phocoenidae, Cetacea) |
title_full |
Life history of the vaquita, Phocoena sinus (Phocoenidae, Cetacea) |
title_fullStr |
Life history of the vaquita, Phocoena sinus (Phocoenidae, Cetacea) |
title_full_unstemmed |
Life history of the vaquita, Phocoena sinus (Phocoenidae, Cetacea) |
title_sort |
life history of the vaquita, phocoena sinus (phocoenidae, cetacea) |
publisher |
Wiley |
publishDate |
1996 |
url |
http://dx.doi.org/10.1111/j.1469-7998.1996.tb05450.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1469-7998.1996.tb05450.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1996.tb05450.x https://zslpublications.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1996.tb05450.x |
genre |
Harbour porpoise |
genre_facet |
Harbour porpoise |
op_source |
Journal of Zoology volume 239, issue 2, page 235-251 ISSN 0952-8369 1469-7998 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1469-7998.1996.tb05450.x |
container_title |
Journal of Zoology |
container_volume |
239 |
container_issue |
2 |
container_start_page |
235 |
op_container_end_page |
251 |
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1809913493690777600 |