Biological Aspects of Swordfish, Xiphias gladius Linnaeus, 1758, Caught  During Tuna Longline Survey in the Indian Seas

Sijo P. Varghese; K. Vijayakumaran; A. Anrose; Vaibhav D. Mhatre

Makale detayları

Biological Aspects of Swordfish, Xiphias gladius Linnaeus, 1758, Caught During Tuna Longline Survey in the Indian Seas

Yazarlar:

Sijo P. Varghese | K. Vijayakumaran | A. Anrose | Vaibhav D. Mhatre

Yayıncı:

Trabzon Su Ürünleri Merkez Araştırma Enstitüsü

Dergi:

Turkish Journal of Fisheries and Aquatic Sciences 2013 Vol.13 Issue 3

Belge Tipi:

Makale

Yayın Tarihi:

5/2013

Belge Dili:

Türkçe

Document ID (Org No.):

2000838200

Sıklık:

Üç Aylık

pISSN:

1303-2712

Anahtar kelimeler:

Özet:

 

Distribution, abundance and biology of swordfish, Xiphias gladius, of the Indian seas were investigated by analyzing the  data gathered during tuna longline surveys conducted by the Fishery Survey of India (FSI). Study undertaken during the  period from 2004 to 2010 revealed swordfish Catch Per Unit Effort of 0.02 numbers in 100 hooks from the Arabian Sea; 0.01  from Bay of Bengal and 0.02 form the Andaman and Nicobar waters. About 16% of the specimens caught were juveniles and  the sex ratio of smaller fishes was in favour of males, whereas, larger specimens were mostly females. Length-weight  relationship established indicated slightly positive allometric growth of the species and length based models revealed  difference in growth between sexes. The growth parameters estimated for females were: asymptotic length (L∞) = 311.11 cm,  growth coefficient (K) = 0.17/yr and age at zero length (t0) = -0.53 yr, whereas, the growth parameters estimated for males  were: L∞ = 243.79 cm, K = 0.22/yr and t0 = -0.37 yr. Diet was dominated by finfishes and cephalopods, while crustaceans  were recorded rarely. Sthenoteuthis oualaniensis was the dominant prey species, followed by Paralepis sp. Spawning area  was identified in the Lakshadweep waters from where mature females with hydrated oocytes were caught during December to  April. Size at 50% maturity for females was estimated at 164.03 cm, which is reached at about four years of age. Mean batch  fecundity was 4.5 million, while the relative fecundity was 37.5 hydrated oocytes per gram of body weight and the diameters  of mature oocytes were in the range of 0.9-1.6 mm. Our results provide preliminary information on the abundance, growth and  biology of this species in the Indian seas which should be useful to fishery managers. 	 	 		 .

 

Distribution, abundance and biology of swordfish, Xiphias gladius, of the Indian seas were investigated by analyzing the  data gathered during tuna longline surveys conducted by the Fishery Survey of India (FSI). Study undertaken during the  period from 2004 to 2010 revealed swordfish Catch Per Unit Effort of 0.02 numbers in 100 hooks from the Arabian Sea; 0.01  from Bay of Bengal and 0.02 form the Andaman and Nicobar waters. About 16% of the specimens caught were juveniles and  the sex ratio of smaller fishes was in favour of males, whereas, larger specimens were mostly females. Length-weight  relationship established indicated slightly positive allometric growth of the species and length based models revealed  difference in growth between sexes. The growth parameters estimated for females were: asymptotic length (L∞) = 311.11 cm,  growth coefficient (K) = 0.17/yr and age at zero length (t0) = -0.53 yr, whereas, the growth parameters estimated for males  were: L∞ = 243.79 cm, K = 0.22/yr and t0 = -0.37 yr. Diet was dominated by finfishes and cephalopods, while crustaceans  were recorded rarely. Sthenoteuthis oualaniensis was the dominant prey species, followed by Paralepis sp. Spawning area  was identified in the Lakshadweep waters from where mature females with hydrated oocytes were caught during December to  April. Size at 50% maturity for females was estimated at 164.03 cm, which is reached at about four years of age. Mean batch  fecundity was 4.5 million, while the relative fecundity was 37.5 hydrated oocytes per gram of body weight and the diameters  of mature oocytes were in the range of 0.9-1.6 mm. Our results provide preliminary information on the abundance, growth and  biology of this species in the Indian seas which should be useful to fishery managers. 	 	 		 .

Makale detayları

Biological Aspects of Swordfish, Xiphias gladius Linnaeus, 1758, Caught During Tuna Longline Survey in the Indian Seas

Yazarlar:

Sijo P. Varghese | K. Vijayakumaran | A. Anrose | Vaibhav D. Mhatre

Yayıncı:

Trabzon Su Ürünleri Merkez Araştırma Enstitüsü

Dergi:

Turkish Journal of Fisheries and Aquatic Sciences 2013 Vol.13 Issue 3

Belge Tipi:

Makale

Yayın Tarihi:

5/2013

Belge Dili:

Türkçe

Document ID (Org No.):

2000838200

Sıklık:

Üç Aylık

pISSN:

1303-2712

Swordfish

longline bycatch

growth parameters

stomach contents

fecundity

Indian Ocean

Sayı

Makale detayları

Biological Aspects of Swordfish, Xiphias gladius Linnaeus, 1758, Caught During Tuna Longline Survey in the Indian Seas

Yazarlar: Sijo P. Varghese | K. Vijayakumaran | A. Anrose | Vaibhav D. Mhatre

Yayıncı: Trabzon Su Ürünleri Merkez Araştırma Enstitüsü

Dergi: Turkish Journal of Fisheries and Aquatic Sciences 2013 Vol.13 Issue 3

Belge Tipi: Makale

Yayın Tarihi: 5/2013

Belge Dili: Türkçe

Document ID (Org No.): 2000838200

Sıklık: Üç Aylık

pISSN: 1303-2712

Swordfish

longline bycatch

growth parameters

stomach contents

fecundity

Indian Ocean

Sayı

Yazarlar:

Sijo P. Varghese | K. Vijayakumaran | A. Anrose | Vaibhav D. Mhatre

Yayıncı:

Trabzon Su Ürünleri Merkez Araştırma Enstitüsü

Dergi:

Turkish Journal of Fisheries and Aquatic Sciences 2013 Vol.13 Issue 3

Belge Tipi:

Makale

Yayın Tarihi:

5/2013

Belge Dili:

Türkçe

Document ID (Org No.):

2000838200

Sıklık:

Üç Aylık

pISSN:

1303-2712