Not all that clear cut : intraspecific morphological variability in Squalus blainville (Risso, 1827) and implications for identification of the species
Of the three species of the genus Squalus that occur in the Mediterranean Sea, S. blainville and S. megalops are very difficult to distinguish. This study assesses the variability in morphological features that have been used to differentiate between these species. Squalus were collected from statio...
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ftunivmalta:oai:www.um.edu.mt:123456789/21113 2023-05-15T16:30:01+02:00 Not all that clear cut : intraspecific morphological variability in Squalus blainville (Risso, 1827) and implications for identification of the species Bonello, Juan José Bonnici, Leanne Ferrari, Alice Cariani, Alessia Schembri, Patrick J. 2016 https://www.um.edu.mt/library/oar//handle/123456789/21113 https://doi.org/10.1017/S0025315415001915 en eng Marine Biological Association of the United Kingdom Bonello, J. J., Bonnici, L., Ferrari, A., Cariani, A., & Schembri, P. J. (2016). Not all that clear cut: intraspecific morphological variability in Squalus blainville (Risso, 1827) and implications for identification of the species. Journal of the Marine Biological Association of the United Kingdom, 96(8), 1585-1596. https://www.um.edu.mt/library/oar//handle/123456789/21113 doi:10.1017/S0025315415001915 info:eu-repo/semantics/openAccess The copyright of this work belongs to the author(s)/publisher. The rights of this work are as defined by the appropriate Copyright Legislation or as modified by any successive legislation. Users may access this work and can make use of the information contained in accordance with the Copyright Legislation provided that the author must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the prior permission of the copyright holder. Greenland shark -- Mediterranean Region Morphology (Animals) Squalus -- Mediterranean Region Squalus -- Anatomy article 2016 ftunivmalta https://doi.org/10.1017/S0025315415001915 2021-10-16T17:55:15Z Of the three species of the genus Squalus that occur in the Mediterranean Sea, S. blainville and S. megalops are very difficult to distinguish. This study assesses the variability in morphological features that have been used to differentiate between these species. Squalus were collected from stations within the 25-nautical mile Fisheries Management Zone around the Maltese Islands; 349 specimens were dissected and categorized into male and female, mature and immature, and individuals were randomly selected from each category to make up a sample of 169 specimens. For each individual, total length and first dorsal fin parameters were measured, and morphology of denticles isolated from the laterodorsal area, of the upper and lower teeth and of the chondrocranium was analysed. The first dorsal spine was shorter that the fin base in 93% of the specimens, which is typical of S. megalops; this character was not related to either gender or maturity. Chondrocrania with one lateral process (typical of S. blainville) and two lateral processes (typical of S. megalops) were present. Teeth from the same individuals showed morphological features that overlap between S. blainville and S. megalops. Both unicuspid (typical of S. megalops) and tricuspid denticles (typical of S. blainville) were observed on the same individuals. Twelve specimens (six having one and six having two lateral chondrocranial processes) were analysed genetically by sequencing of the mtDNA marker Cytochrome Oxidase Subunit I (COI). All resulted to be S. blainville showing that intraspecific variability in supposedly diagnostic morphological features is large enough to render these unreliable to tell apart these two species, especially in the field. peer-reviewed Article in Journal/Newspaper Greenland University of Malta: OAR@UM Greenland Journal of the Marine Biological Association of the United Kingdom 96 8 1585 1596 |
institution |
Open Polar |
collection |
University of Malta: OAR@UM |
op_collection_id |
ftunivmalta |
language |
English |
topic |
Greenland shark -- Mediterranean Region Morphology (Animals) Squalus -- Mediterranean Region Squalus -- Anatomy |
spellingShingle |
Greenland shark -- Mediterranean Region Morphology (Animals) Squalus -- Mediterranean Region Squalus -- Anatomy Bonello, Juan José Bonnici, Leanne Ferrari, Alice Cariani, Alessia Schembri, Patrick J. Not all that clear cut : intraspecific morphological variability in Squalus blainville (Risso, 1827) and implications for identification of the species |
topic_facet |
Greenland shark -- Mediterranean Region Morphology (Animals) Squalus -- Mediterranean Region Squalus -- Anatomy |
description |
Of the three species of the genus Squalus that occur in the Mediterranean Sea, S. blainville and S. megalops are very difficult to distinguish. This study assesses the variability in morphological features that have been used to differentiate between these species. Squalus were collected from stations within the 25-nautical mile Fisheries Management Zone around the Maltese Islands; 349 specimens were dissected and categorized into male and female, mature and immature, and individuals were randomly selected from each category to make up a sample of 169 specimens. For each individual, total length and first dorsal fin parameters were measured, and morphology of denticles isolated from the laterodorsal area, of the upper and lower teeth and of the chondrocranium was analysed. The first dorsal spine was shorter that the fin base in 93% of the specimens, which is typical of S. megalops; this character was not related to either gender or maturity. Chondrocrania with one lateral process (typical of S. blainville) and two lateral processes (typical of S. megalops) were present. Teeth from the same individuals showed morphological features that overlap between S. blainville and S. megalops. Both unicuspid (typical of S. megalops) and tricuspid denticles (typical of S. blainville) were observed on the same individuals. Twelve specimens (six having one and six having two lateral chondrocranial processes) were analysed genetically by sequencing of the mtDNA marker Cytochrome Oxidase Subunit I (COI). All resulted to be S. blainville showing that intraspecific variability in supposedly diagnostic morphological features is large enough to render these unreliable to tell apart these two species, especially in the field. peer-reviewed |
format |
Article in Journal/Newspaper |
author |
Bonello, Juan José Bonnici, Leanne Ferrari, Alice Cariani, Alessia Schembri, Patrick J. |
author_facet |
Bonello, Juan José Bonnici, Leanne Ferrari, Alice Cariani, Alessia Schembri, Patrick J. |
author_sort |
Bonello, Juan José |
title |
Not all that clear cut : intraspecific morphological variability in Squalus blainville (Risso, 1827) and implications for identification of the species |
title_short |
Not all that clear cut : intraspecific morphological variability in Squalus blainville (Risso, 1827) and implications for identification of the species |
title_full |
Not all that clear cut : intraspecific morphological variability in Squalus blainville (Risso, 1827) and implications for identification of the species |
title_fullStr |
Not all that clear cut : intraspecific morphological variability in Squalus blainville (Risso, 1827) and implications for identification of the species |
title_full_unstemmed |
Not all that clear cut : intraspecific morphological variability in Squalus blainville (Risso, 1827) and implications for identification of the species |
title_sort |
not all that clear cut : intraspecific morphological variability in squalus blainville (risso, 1827) and implications for identification of the species |
publisher |
Marine Biological Association of the United Kingdom |
publishDate |
2016 |
url |
https://www.um.edu.mt/library/oar//handle/123456789/21113 https://doi.org/10.1017/S0025315415001915 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_relation |
Bonello, J. J., Bonnici, L., Ferrari, A., Cariani, A., & Schembri, P. J. (2016). Not all that clear cut: intraspecific morphological variability in Squalus blainville (Risso, 1827) and implications for identification of the species. Journal of the Marine Biological Association of the United Kingdom, 96(8), 1585-1596. https://www.um.edu.mt/library/oar//handle/123456789/21113 doi:10.1017/S0025315415001915 |
op_rights |
info:eu-repo/semantics/openAccess The copyright of this work belongs to the author(s)/publisher. The rights of this work are as defined by the appropriate Copyright Legislation or as modified by any successive legislation. Users may access this work and can make use of the information contained in accordance with the Copyright Legislation provided that the author must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the prior permission of the copyright holder. |
op_doi |
https://doi.org/10.1017/S0025315415001915 |
container_title |
Journal of the Marine Biological Association of the United Kingdom |
container_volume |
96 |
container_issue |
8 |
container_start_page |
1585 |
op_container_end_page |
1596 |
_version_ |
1766019740783869952 |