Some morphological and biological aspects of longnosed skate, Dipturus oxyrinchus (Elasmobranchii: Rajiformes: Rajidae), in Syrian marine waters (eastern Mediterranean)
Background. Dipturus oxyrinchus (Linnaeus, 1758) is a common skate in Syrian elasmobranch fishery. This species is listed as an Endangered cartilaginous species on the International Union for the Conservation of Nature (IUCN) Red List. Although heavily exploited, until now, no study has been perform...
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Online Access: | https://doi.org/10.3750/AIEP/02283 https://doaj.org/article/44e2c7596c08493a8c5176a44b5b9e1b |
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ftdoajarticles:oai:doaj.org/article:44e2c7596c08493a8c5176a44b5b9e1b 2023-05-15T15:56:11+02:00 Some morphological and biological aspects of longnosed skate, Dipturus oxyrinchus (Elasmobranchii: Rajiformes: Rajidae), in Syrian marine waters (eastern Mediterranean) H.H Alkusairy A.A. Saad 2017-12-01T00:00:00Z https://doi.org/10.3750/AIEP/02283 https://doaj.org/article/44e2c7596c08493a8c5176a44b5b9e1b EN eng Pensoft Publishers https://aiep.pensoft.net/article/26748/download/pdf/ https://aiep.pensoft.net/article/26748/download/xml/ https://aiep.pensoft.net/article/26748/ https://doaj.org/toc/1734-1515 doi:10.3750/AIEP/02283 1734-1515 https://doaj.org/article/44e2c7596c08493a8c5176a44b5b9e1b Acta Ichthyologica et Piscatoria, Vol 47, Iss 4, Pp 371-383 (2017) maturity reproductive cycle fecundity Syrian co Aquaculture. Fisheries. Angling SH1-691 article 2017 ftdoajarticles https://doi.org/10.3750/AIEP/02283 2022-12-30T21:37:34Z Background. Dipturus oxyrinchus (Linnaeus, 1758) is a common skate in Syrian elasmobranch fishery. This species is listed as an Endangered cartilaginous species on the International Union for the Conservation of Nature (IUCN) Red List. Although heavily exploited, until now, no study has been performed on this skate along the Syrian coast in the Levantine basin. This study focuses on the determination of the reproductive period, size at maturity and fecundity of D. oxyrhinchus. Materials and methods. Total length and total weight were determined for 249 specimens of the longnosed skate, captured off Syrian coast. Skates collected were measured and weighed according to standard procedures. Based on the acquired measurements the following relations were determined: disc width–total weight (DW–TW), total weight–total length (TW–TL), total weight–disc width (TW–DW), and total length–disc width (TL–DW). Median size (TL50) at maturity was estimated according to commonly accepted methods. Hepatosomatic index (HSI) and gonadosomatic index (GSI) were calculated for males and females. The proportion of the occurrence of developmental stages were noted seasonally. Ovarian fecundity was calculated based on ripe follicles in both ovaries of mature females. Fecundity, expressed as annual egg production per female. Tests for significance (P < 0.05) were performed by using ANOVA, Student t-test, and the chi-square test. In the relations TW–TL and TW–DW, comparisons of curves were carried out by using ANCOVA Results. The observed sex ratio was 58.2% ÷ 40.2% (female ÷ male). Mean body measurements of females (n = 14) were slightly higher than males (n = 8). The total length of females ranged from 34.1 to 100.0 cm and males from 34.5 to 81.6 cm. The total length–total weight, disc width–total weight, and total length–disc width relations were TW = 0.0009TL3.35 and TW = 0.0033DW3.34and DW = 0.6894TL + 0.281, respectively, for all sexes combined. Median size (TL50) at maturity were estimated as TL50 = 79.5 cm for females (n = 149) ... Article in Journal/Newspaper Common skate Directory of Open Access Journals: DOAJ Articles Acta Ichthyologica et Piscatoria 47 4 371 383 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
maturity reproductive cycle fecundity Syrian co Aquaculture. Fisheries. Angling SH1-691 |
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maturity reproductive cycle fecundity Syrian co Aquaculture. Fisheries. Angling SH1-691 H.H Alkusairy A.A. Saad Some morphological and biological aspects of longnosed skate, Dipturus oxyrinchus (Elasmobranchii: Rajiformes: Rajidae), in Syrian marine waters (eastern Mediterranean) |
topic_facet |
maturity reproductive cycle fecundity Syrian co Aquaculture. Fisheries. Angling SH1-691 |
description |
Background. Dipturus oxyrinchus (Linnaeus, 1758) is a common skate in Syrian elasmobranch fishery. This species is listed as an Endangered cartilaginous species on the International Union for the Conservation of Nature (IUCN) Red List. Although heavily exploited, until now, no study has been performed on this skate along the Syrian coast in the Levantine basin. This study focuses on the determination of the reproductive period, size at maturity and fecundity of D. oxyrhinchus. Materials and methods. Total length and total weight were determined for 249 specimens of the longnosed skate, captured off Syrian coast. Skates collected were measured and weighed according to standard procedures. Based on the acquired measurements the following relations were determined: disc width–total weight (DW–TW), total weight–total length (TW–TL), total weight–disc width (TW–DW), and total length–disc width (TL–DW). Median size (TL50) at maturity was estimated according to commonly accepted methods. Hepatosomatic index (HSI) and gonadosomatic index (GSI) were calculated for males and females. The proportion of the occurrence of developmental stages were noted seasonally. Ovarian fecundity was calculated based on ripe follicles in both ovaries of mature females. Fecundity, expressed as annual egg production per female. Tests for significance (P < 0.05) were performed by using ANOVA, Student t-test, and the chi-square test. In the relations TW–TL and TW–DW, comparisons of curves were carried out by using ANCOVA Results. The observed sex ratio was 58.2% ÷ 40.2% (female ÷ male). Mean body measurements of females (n = 14) were slightly higher than males (n = 8). The total length of females ranged from 34.1 to 100.0 cm and males from 34.5 to 81.6 cm. The total length–total weight, disc width–total weight, and total length–disc width relations were TW = 0.0009TL3.35 and TW = 0.0033DW3.34and DW = 0.6894TL + 0.281, respectively, for all sexes combined. Median size (TL50) at maturity were estimated as TL50 = 79.5 cm for females (n = 149) ... |
format |
Article in Journal/Newspaper |
author |
H.H Alkusairy A.A. Saad |
author_facet |
H.H Alkusairy A.A. Saad |
author_sort |
H.H Alkusairy |
title |
Some morphological and biological aspects of longnosed skate, Dipturus oxyrinchus (Elasmobranchii: Rajiformes: Rajidae), in Syrian marine waters (eastern Mediterranean) |
title_short |
Some morphological and biological aspects of longnosed skate, Dipturus oxyrinchus (Elasmobranchii: Rajiformes: Rajidae), in Syrian marine waters (eastern Mediterranean) |
title_full |
Some morphological and biological aspects of longnosed skate, Dipturus oxyrinchus (Elasmobranchii: Rajiformes: Rajidae), in Syrian marine waters (eastern Mediterranean) |
title_fullStr |
Some morphological and biological aspects of longnosed skate, Dipturus oxyrinchus (Elasmobranchii: Rajiformes: Rajidae), in Syrian marine waters (eastern Mediterranean) |
title_full_unstemmed |
Some morphological and biological aspects of longnosed skate, Dipturus oxyrinchus (Elasmobranchii: Rajiformes: Rajidae), in Syrian marine waters (eastern Mediterranean) |
title_sort |
some morphological and biological aspects of longnosed skate, dipturus oxyrinchus (elasmobranchii: rajiformes: rajidae), in syrian marine waters (eastern mediterranean) |
publisher |
Pensoft Publishers |
publishDate |
2017 |
url |
https://doi.org/10.3750/AIEP/02283 https://doaj.org/article/44e2c7596c08493a8c5176a44b5b9e1b |
genre |
Common skate |
genre_facet |
Common skate |
op_source |
Acta Ichthyologica et Piscatoria, Vol 47, Iss 4, Pp 371-383 (2017) |
op_relation |
https://aiep.pensoft.net/article/26748/download/pdf/ https://aiep.pensoft.net/article/26748/download/xml/ https://aiep.pensoft.net/article/26748/ https://doaj.org/toc/1734-1515 doi:10.3750/AIEP/02283 1734-1515 https://doaj.org/article/44e2c7596c08493a8c5176a44b5b9e1b |
op_doi |
https://doi.org/10.3750/AIEP/02283 |
container_title |
Acta Ichthyologica et Piscatoria |
container_volume |
47 |
container_issue |
4 |
container_start_page |
371 |
op_container_end_page |
383 |
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