Age and growth in Phocoena phocoena Linnaeus, 1758 (Cetacea, Odontoceti) from the North Sea
Data and material are collected from 106 Harbour Porpoises (P. phocoena) from the southern part of the North Sea. All animals are accidentally caught or found stranded. The greatest length for males in the sample is 151 cm, for females 186 cm. For detailed analysis of body measurements, 30 males and...
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ftnaturalis:oai:naturalis:504449 2023-05-15T17:59:12+02:00 Age and growth in Phocoena phocoena Linnaeus, 1758 (Cetacea, Odontoceti) from the North Sea Utrecht, W.L. van 1978 application/pdf http://www.repository.naturalis.nl/record/504449 http://www.repository.naturalis.nl/document/548103 unknown http://www.repository.naturalis.nl/record/504449 http://www.repository.naturalis.nl/document/548103 (c) Naturalis Bijdragen tot de Dierkunde (0067-8546) vol.48 (1978) nr.1 p.16 Article / Letter to the editor 1978 ftnaturalis 2022-09-01T06:21:58Z Data and material are collected from 106 Harbour Porpoises (P. phocoena) from the southern part of the North Sea. All animals are accidentally caught or found stranded. The greatest length for males in the sample is 151 cm, for females 186 cm. For detailed analysis of body measurements, 30 males and 37 females are selected, while from 20 males and 34 females teeth are used for age analysis. The analysis of the body measurements shows sexual dimorphism in the anterior and posterior part of the back, in the flukes and flippers and in the position of the genital slit. The maximum number of dentinal layers found in the teeth is 12. Males attain sexual maturity after the deposition of 5 dentinal layers, females when 6 layers are formed, at a body length of about 135 cm and 150 cm, respectively. Some evidence is found that the population of P. phocoena from the North Sea has a lower growth rate than the population from Canadian waters. The gestation period is estimated to be eleven months, the peak of the birth period being in June. The animals are born at a length varying between 67 cm to 80 cm. Growth of the visceral organs is isogonic. The mean weight of the organs is greater in females than in males. Article in Journal/Newspaper Phocoena phocoena Naturalis Digital Academic Repository (National Museum of Natural History in the Netherlands) |
institution |
Open Polar |
collection |
Naturalis Digital Academic Repository (National Museum of Natural History in the Netherlands) |
op_collection_id |
ftnaturalis |
language |
unknown |
description |
Data and material are collected from 106 Harbour Porpoises (P. phocoena) from the southern part of the North Sea. All animals are accidentally caught or found stranded. The greatest length for males in the sample is 151 cm, for females 186 cm. For detailed analysis of body measurements, 30 males and 37 females are selected, while from 20 males and 34 females teeth are used for age analysis. The analysis of the body measurements shows sexual dimorphism in the anterior and posterior part of the back, in the flukes and flippers and in the position of the genital slit. The maximum number of dentinal layers found in the teeth is 12. Males attain sexual maturity after the deposition of 5 dentinal layers, females when 6 layers are formed, at a body length of about 135 cm and 150 cm, respectively. Some evidence is found that the population of P. phocoena from the North Sea has a lower growth rate than the population from Canadian waters. The gestation period is estimated to be eleven months, the peak of the birth period being in June. The animals are born at a length varying between 67 cm to 80 cm. Growth of the visceral organs is isogonic. The mean weight of the organs is greater in females than in males. |
format |
Article in Journal/Newspaper |
author |
Utrecht, W.L. van |
spellingShingle |
Utrecht, W.L. van Age and growth in Phocoena phocoena Linnaeus, 1758 (Cetacea, Odontoceti) from the North Sea |
author_facet |
Utrecht, W.L. van |
author_sort |
Utrecht, W.L. van |
title |
Age and growth in Phocoena phocoena Linnaeus, 1758 (Cetacea, Odontoceti) from the North Sea |
title_short |
Age and growth in Phocoena phocoena Linnaeus, 1758 (Cetacea, Odontoceti) from the North Sea |
title_full |
Age and growth in Phocoena phocoena Linnaeus, 1758 (Cetacea, Odontoceti) from the North Sea |
title_fullStr |
Age and growth in Phocoena phocoena Linnaeus, 1758 (Cetacea, Odontoceti) from the North Sea |
title_full_unstemmed |
Age and growth in Phocoena phocoena Linnaeus, 1758 (Cetacea, Odontoceti) from the North Sea |
title_sort |
age and growth in phocoena phocoena linnaeus, 1758 (cetacea, odontoceti) from the north sea |
publishDate |
1978 |
url |
http://www.repository.naturalis.nl/record/504449 http://www.repository.naturalis.nl/document/548103 |
genre |
Phocoena phocoena |
genre_facet |
Phocoena phocoena |
op_source |
Bijdragen tot de Dierkunde (0067-8546) vol.48 (1978) nr.1 p.16 |
op_relation |
http://www.repository.naturalis.nl/record/504449 http://www.repository.naturalis.nl/document/548103 |
op_rights |
(c) Naturalis |
_version_ |
1766167966878007296 |