Reproduction and Embryonic Development of Spiny Dogfish (Squalus acanthias) in the Strait of Georgia, British Columbia

1977 ◽  
Vol 34 (9) ◽  
pp. 1286-1292 ◽  
Author(s):  
Barry C. Jones ◽  
Glen H. Geen
Keyword(s):  
Embryonic Development ◽  
Length Distribution ◽  
Uterine Cavity ◽  
Mesh Size ◽  
Squalus Acanthias ◽  
Population Characteristics ◽  
Spiny Dogfish ◽  
Total Catch ◽  
Strait Of Georgia ◽  
Males And Females

Lengths at 50% maturity of spiny dogfish (Squalus acanthias) in the Strait of Georgia, B.C., are 78.5 and 93.5 cm, corresponding to ages 19 and 29 yr, for males and females, respectively. Modal lengths of mature males and females are 85 and 100 cm, respectively.Mating occurs from October to January, with a peak in December. Males are capable of mating every year, with smaller dogfish mating earlier in the year than larger ones. Females mate every 2nd yr. Ovulation of 4 cm diam eggs closely follows mating. The fertilized eggs are enclosed in gelatinous capsules for 4 mo after which the embryos are released into the uterine cavity. The external yolk supply of the embryos is totally absorbed by parturition, although the internal yolk is not fully utilized until 2 mo later. Parturition occurs from September to January, with a peak in November. Gestation is roughly 23 mo. Breeding females produce a mean of 7.14 progeny.These population characteristics indicate that regulation of a future fishery should be by total catch limit rather than net mesh size selection. Key words: spiny dogfish, reproduction, length distribution, survivorship, fecundity, fishery regulation

Biology and Management of Dogfish Sharks

2009 ◽  
Keyword(s):  
Life History ◽  
Pacific Coast ◽  
Puget Sound ◽  
Squalus Acanthias ◽  
Spiny Dogfish ◽  
Dietary Analysis ◽  
Strait Of Georgia ◽  
Food Items ◽  
Abundance Estimates ◽  
Commercial Species

Abstract.—Spiny dogfish <em>Squalus acanthias </em>have been an important commercial species on Canada’s Pacific coast for more than 130 years. In this study we show that the spiny dogfish life history results in juveniles remaining in pelagic waters for 10–15 years after birth, with lengths up to about 60 cm. Abundance estimates show that the numbers of these young dogfish, as well as some older dogfish in the pelagic waters, appear to represent a relatively large percentage of the population in these two regions. Dietary analysis shows that while euphausiids and teleosts constitute the major food items, regardless of size/age, dogfish feed on a number of species within the ecosystem. After about 15 years, there is a movement into demersal habitats where individuals eventually mature. Because dogfish are long lived, and because they are found throughout the pelagic zone and demersal habitats, it is probable that they play a key role in the Strait of Georgia and Puget Sound ecosystems.

Maturity, reproductive cycle and fecundity of the spiny dogfish Squalus acanthias (Chondrichthyes: Squalidae) off the Languedocian coast (southern France, northern Mediterranean)

2011 ◽  
Vol 91 (8) ◽  
pp. 1627-1635 ◽  
Author(s):  
C. Capapé ◽  
C. Reynaud
Keyword(s):  
Reproductive Cycle ◽  
Squalus Acanthias ◽  
Hepatosomatic Index ◽  
Spiny Dogfish ◽  
Male And Female ◽  
Southern France ◽  
Short Period ◽  
Wide Range ◽  
Males And Females ◽  
Near Term

The spiny dogfish Squalus acanthias is widely distributed in Atlanto-Mediterranean regions, being captured off the Languedocian coast (southern France, northern Mediterranean), despite a decline of landings. The male and female sexually matured between 635–700 mm and 860–880 mm total length (TL), respectively. The largest male and female were 800 mm and 1110 mm TL, respectively and weighed 2220 g and 8900 g, respectively. There was a significant relationship for total mass versus TL, and liver mass versus TL between males and females. The diameter of the largest yolky oocytes ranged between 43 and 47 mm (mean 45.08 ± 0.98), while the mass ranged between 29.5 and 37.4 g (mean 31.79 ± 2.20). Near- term embryos ranged from 245 to 271 mm TL (mean: 258.85 ± 7.28) and weighed from 47.5 to 55.9 g (mean 53.35 ± 2.26). Ovarian fecundity ranged from 6 to 15 (mean = 10.38 ± 2.66). Uterine fecundity or litter size ranged from 4 to 12 (mean = 8.15 ± 2.07). Both fecundities showed a positive relationship with TL of females. A chemical balance of development based on mean dry masses of yolky oocytes and near-term embryos was 0.87 and suggested that S. acanthias is a pure lecithotrophic species. Hepatosomatic index (HSI) and gonadosomatic index (GSI) significantly increased with size in both males and females. HSI reached the highest values in both sub-adult and adult specimens, reflecting the role of the liver in the gonadal production as well as in buoyancy, while in the GSI the highest values were observed in pregnant females. Vitellogenesis proceeds in parallel with embryonic development. Near-term females were captured in different months of the year while a short period of resting could not be excluded between parturition and the beginning of a new pregnancy, so it appears difficult to delineate the length of gestation. However, a reproductive cycle with a wide range from 18 to 24 months remains a suitable hypothesis.

Biology and Management of Dogfish Sharks

2009 ◽  
Keyword(s):  
Reproductive Cycle ◽  
Reproductive Tract ◽  
Puget Sound ◽  
Squalus Acanthias ◽  
Spiny Dogfish ◽  
Embryo Size ◽  
Adult Females ◽  
Males And Females ◽  
One Year ◽  
Appearance Changes

Abstract.—The fishery for spiny dogfish <em>Squalus acanthias </em>in Washington State has been ongoing for over a century. Management efforts have historically been limited and recent interest in increasing management efforts has led to renewed interest in the biology of the species. This project was undertaken to aid in management by describing the reproductive cycle of the dogfish in Puget Sound. Reproductive tracts were sampled from 170 male and 358 female dogfish from the catch of a commercial trawler over one year. Size at 50% maturity was 89.9 cm for females and 74.1 cm for males (total length extended). Reproductive stages were developed for adult females based on the proportion of yolk absorbed by the developing embryo. Size, weight, and appearance changes in the reproductive tract for both males and females throughout maturation and reproduction are described. There did not appear to be a significant seasonality to the reproductive timing, in that the onset of pregnancy and pupping were observed year round, however, peaks in activity were observed in December for the onset of pregnancy and October for pupping.

Age Determination of an Elasmobranch (Squalus acanthias) by X-ray Spectrometry

1977 ◽  
Vol 34 (1) ◽  
pp. 44-48 ◽  
Author(s):  
Barry C. Jones ◽  
Glen H. Geen
Keyword(s):  
Age Determination ◽  
Element Composition ◽  
Squalus Acanthias ◽  
Spiny Dogfish ◽  
Strait Of Georgia ◽  
X Ray ◽  
Spectrometric Technique

Ages of spiny dogfish (Squalus acanthias) in the Strait of Georgia, B.C., have been estimated by an X-ray spectrometric technique which involves measuring variations in the element composition within vertebrae.

Mercury Content of Spiny Dogfish (Squalus acanthias) in the Strait of Georgia, British Columbia

1972 ◽  
Vol 29 (10) ◽  
pp. 1487-1490 ◽  
Author(s):  
C. R. Forrester ◽  
K. S. Ketchen ◽  
C. C. Wong
Keyword(s):  
Total Mercury ◽  
River Estuary ◽  
Mercury Content ◽  
Squalus Acanthias ◽  
Spiny Dogfish ◽  
Fraser River ◽  
Female Fish ◽  
Male And Female ◽  
Strait Of Georgia ◽  
Total Length

Total mercury content of Squalus acanthias sampled in the Strait of Georgia reached levels of 0.5 ppm at fish lengths of 72 and 77 cm for male and female fish, respectively. For any given length above 65 cm the mercury content was higher among males than females and higher in samples taken off the Fraser River Estuary than in other areas of the Strait. Levels of mercury reached 1.7 ppm in males (to 95 cm in total length) and almost 2.0 ppm in females (to 120 cm in total length).

scholarly journals BEBERAPA ASPEK BIOLOGI IKAN TENGGIRI PAPAN (Scomberomorus guttatus) DI PERAIRAN CILACAP DAN SEKITARNYA

2017 ◽  
Vol 8 (3) ◽  
pp. 191
Author(s):  
Yoke Hani Restiangsih ◽  
Tegoeh Noegoho ◽  
Karsono Wagiyo
Keyword(s):  
Sex Ratio ◽  
Length Distribution ◽  
Stage Iv ◽  
Mesh Size ◽  
Maturity Stage ◽  
Biological Aspect ◽  
Multiple Spawner ◽  
Males And Females ◽  
King Mackerel ◽  
First Maturity

Tenggiri papan (Scomberomorus guttatus)merupakan ikan yangmemiliki nilai ekonomis penting dan banyak tertangkap dengan gillnet di perairan Cilacap dan sekitarnya. Pada saat ini terdapat kecenderungan ukuran individu yang mengecil. Tujuan Penelitian ini adalah mengetahui beberapa aspek biologi ikan tenggiri papan meliputi sebaran ukuran panjang, hubungan panjang-bobot, nisbah kelamin, tingkat kematangan gonad dan ukuran rata-rata pertama kali matang gonad, berdasarkan hasil tangkapan gillnet yang didaratkan di Pelabuhan Perikanan Samudera Cilacap pada bulan Februari sampai Desember 2013. Hasil penelitian menunjukkan ukuran panjang cagak berkisar antara 11 – 67cm. Pola pertumbuhan ikan tenggiri papan bersifat isometric dimana pertambahan panjang dan bobotnya seimbang. Nisbah kelamin jantan terhadap betina sebagai 1 : 0,7. Panjang pertama kali ikan tertangkap (Lc) dengan gillnet berukuran mata jaring 3 inchi sebesar 32,7 cmFL dan pertama kalimatang gonad (Lm) sebesar 42,34 cmFL. TingkatKematanganGonad (TKG) ikan jantan dan betina didominasi oleh stadia IV terutama pada bulan Februari dan Mei. Hasil penelitian ini menunjukkan dugaan awal masa pemijahan terjadi pada bulan Maret dan Juni, dengan demikian pemijahan dilakukan secara bertahap. Indo-Pasific king mackerel (Scomberomorus guttatus) is one of fish that has an important economic value.The species were many caught by gillnet in Cilacap and adjacent waters. Research was conducted to determine biological aspect of Indo-Pasific king mackerel that includes length distribution, length-weight relationship, sex ratio, maturity stage and length at first mature, based on monthly catches landed at Cilacap fishing port during February to December 2013. The results showed that folk length ranged from 11 to 67 cm. The growth pattern are isometric. The condition of sex ratio ofmales to females was 1 : 0,7. Length at first capture(Lc) by gillnet with mesh size of 3 inches was 32.7 cmFL and length at first maturity(Lm) was 42.34 cmFL. The gonade maturity stage of males and females were dominated by stage IV mainly in Febuary and May. It was indicated that spawning seasons occured in March and June. It was indicated that the fish has multiple spawner.

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