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  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 41 (1992), S. 0 
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Metamorphosis in cod, Gadus morhua L., was investigated with respect to morphological changes in the alimentary tract (mouth, stomach and pyloric caeca) and external characters (finfold and fin development). Morphometric measurements and histological investigations were made on both larvae and juveniles and all fish lengths are given as standard length. Median unpaired fins started to develop when the fish were 9–10 mm in length. The larval median finfold was resorbed when fish reached a size of 11–15 mm. The vertebrae were formed in fish of 11–20 mm. The supraterminal mouth, seen in larvae 〈12 mm, changed gradually to a sub-terminal position in juveniles larger than 65 mm. The development of the stomach and pyloric caeca started at 15 mm and the juvenile form was seen in fish of 40 mm. The ability to store and grind food particles in the stomach developed gradually as fish increased in size from 20 to 40 mm. Compared to many other teleost species, cod juveniles are relatively large when the stomach and pyloric caeca become fully developed. These findings may have important implications for both start-feeding of cod larvae and the weaning of juveniles on to artificial diets.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 59 (2001), S. 0 
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Wolffish Anarhichas lupus (Anarhichadidae) hatch from large demersal eggs (c. 5–6 mm) after a long incubation period (c. 800–1000 degree days) at 20–25 mm LT with a juvenile appearance: a small yolk sac, pigmented but partly transparent skin densely supplied with mucous cells, well developed body musculature and a cartilaginous skeleton. The results of histomorphological studies illustrate the apparent functionality of tissues and organs at hatching. The mucosa of the oral cavity and various parts of the digestive channel are well differentiated and the cellular characteristics are described within each region. A stomach with gastric glands is established before hatching. The pancreas has well developed endo- and exocrine tissue and the hepatocytes are vacuolized. The kidney tissue has numerous tubuli and haematopoietic tissue in the bilobed head region. The spleen, thymus and thyroid glands also appear mature. Cones are dominant in the visual cell layer of the retina.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Aquaculture research 32 (2001), S. 0 
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Temperature influenced the developmental rate, survival and early growth of eggs and embryos of spotted wolffish, Anarhichas minor (Olafsen), an interesting candidate for cold water cultivation. The total incubation period decreased from 220 days at 4 °C (880 daydegrees), to 177 days at 6 °C (1062 daydegrees) and 150 days at 8 °C (1200 daydegrees) in these experiments. The proportion of normal embryos and survival of eggs until hatching were highest when the eggs were incubated at 6 °C. During the incubation period, the embryo and yolk sac size at 280 daydegrees was not significantly different but at 850 daydegrees the embryo size was inversely related to temperature and the remaining yolk sac size positively correlated with the incubation temperature. The transformation of yolk to body mass during incubation appeared to be most efficient at 4 °C, and the embryos hatched with a larger visible yolk sac at 6 and 8 °C. The largest larvae (wet-weight) hatched from the largest eggs and the egg groups incubated at the lowest temperature (4 °C). There was no effect of temperature on meristic characters. During 6 weeks post-hatching, all larvae from the three temperature groups were fed formulated dry feed in excess at 8 °C in low water-level raceway systems. During startfeeding, the larvae from eggs incubated at the lowest temperature (4 °C) showed the highest growth rates (SGR). Best survival of larvae was noted among batches incubated at 6 °C.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Aquaculture research 30 (1999), S. 0 
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: The spotted wolffish Anarhichas minor (Olafsen), with its rich and tasty fillets, popular skin and high growth rates in captivity, is a promising candidate for cold-water aquaculture. We have established a production line for the wolffish during 5 years of active research on the biology of the species. Our broodstock, sampled from the Barents Sea, has mainly spawned during autumn. The females must be stripped as soon as possible after ovulation. The best egg batches have shown c. 100% fertilization and survival rates between 60% and 80% during the 800- to 960-daydegrees-long incubation period. Rearing temperatures of 6 °C, 8 °C, ambient and decreasing temperatures have turned out to be satisfactory for survival. Treatment with 150 p.p.m. glutardialdehyde twice a month is recommended to control microorganism growth on eggs. Premature hatching has been a problem in individual egg batches; the reasons are not fully understood. Normally hatched individuals are ≈ 22 mm long and well developed, with a small yolk sac, which is completely resorbed after about 4 weeks at 6–8 °C. The fry have been successfully start fed on formulated feed as well as Artemia. Highest early growth rates have been noted at 8 °C, but overall survival was best at 6 °C. On-growth of spotted wolffish juveniles fed formulated dry floating feed at low temperatures in shallow raceways has been promising. After 2, 3 and 4 years, the mean weights of the first generation produced in aquaculture were 0.7, 2.7 and 5.1 kg respectively. These individuals now make up the broodstock at a recently established commercial production facility.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0044-8486
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-2056
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The snailfish family Liparididae was well represented in bottom trawl hauls (205–370 m) from the Spitsbergen area, with Liparis gibbus being the dominant species. Careproctus reinhardti was less numerous. The present paper is based on 539 specimens of C. gibbus (size range 6–25cm) and 120 specimens of L. reinhardti (size range 5–26 cm). Both species showed a rather similar size and age distribution. The stomach contents reveal that both snailfish species feed both benthically and pelagically. Crustaceans, especially amphipods and decapods, were the most common prey items. With increasing size of the fish, the decapod Pandalus borealis becomes more important, particularly for L. gibbus. Juvenile Liparis (1.3–4.3 cm in length) were found pelagically (35–200 m), and their diet mainly consisted of copepods and young hyperiid amphipods.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fertilized Atlantic halibut (Hippoglossus hippoglossus L.) eggs in different developmental stages (Days 0 to 18) were sampled from plankton in North Norway in February 1986 and analysed for lipid classes and fatty acid content. In unfertilized ovulated eggs taken from ripe fish caught in 1983/1984, polar and neutral lipids comprised ca. 71 and 30% of the total lipids, respectively, decreasing and increasing to 67 and 33%, respectively, in Stage III (11 to 18 d old) fertilized eggs. Of the polar lipids, phosphatidylcholine decreased markedly from 62% in unfertilized ovulated eggs to ca. 40% in Stage I (0 to 3 d old) fertilized eggs, while phosphatidylethanolamine increased from ca. 7 to 33%. Triacylglycerols, the major neutral lipids, increased from ca. 13% in unfertilized ovulated eggs to 16% in Stage III fertilized eggs. The total lipid in Stage I fertilized eggs had relatively low levels of polyunsaturated fatty acids (PUFA), with (n-3) PUFA accounting for only ca. 25% of the total fatty acids. The (n-3) PUFA increased to ca. 40% of the total fatty acids in Stage III, while the (n-3): (n-6) ratio increased from 4.1 to 7.0.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Seasonal lipid analyses were performed on the gonads and residual bodies of Ctenodiscus crispatus (Retzius) and Asterias lincki (Müller & Troschel), collected from Balsfjorden, northern Norway during March 1978–February 1980. The ovaries of both species had high percentages of total lipid (in the region of 60% of the dry weight) that were relatively constant throughout the season. Testes from both species had in the region of 20% of their dry weight as lipid, again with little seasonal variation. The majority of the total lipid in the ovaries of C. crispatus was accounted for by alkyldiacylglycerols and there was little seasonal variation in lipid class composition. Phospholipid accounted for the bulk of the lipid in the testes of C. crispatus, where alkyldiacylglycerols were present but in minor amounts. A slight degree of seasonal variation occurred in the composition of testis lipid in that maximal percentages of triacylglycerols and alkyldiacylglycerols occurred in January–April. The ovaries of A. lincki contained both triacylglycerols and alkyldiacylglycerols as major neutral lipids. Significant seasonal variation occurred in lipid class composition in the ovaries in that neutral lipids showed transient minima in February–April. The testes of A. lincki had substantial amounts of both triacylglycerols and alkyldiacylglycerols: maximal percentages of these lipids occurred in January–March. Analyses of gonads of near-mature Pteraster militaris (O. F. Müller) revealed that the ovaries were rich in lipid that was predominantly alkyldiacylglycerols, whereas the testes had much lower levels of lipid accounted for mainly by phospholipids. The residual bodies of all three asteroids had significant but small amounts of alkyldiacylglycerols in their lipids. A. lincki had triacylglycerols as a major lipid class in its body lipids, whereas in C. crispatus the major body lipid was phospholipid. Little seasonal variation was seen in the composition of the residual body lipid of either C. crispatus or A. lincki. The results are consistent with an aseasonal reproductive pattern in C. crispatus, although a main breeding activity occurred in mid-winter. A. lincki is a more seasonal breeder, but also had maximal activity in winter. Irrespective of their breeding habits, all three asteroids produced eggs rich in alkyldiacylglycerols. A major role for this lipid in the development of the large lecithotrophic eggs of asteroids is indicated.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fatty acid analyses of lipids in the asteroids Ctenodiscus crispatus (Retzius), Asterias lincki (Müller and Troschel) and Pteraster militaris (O. F. Müller) collected in Balsfjorden, near Tromsø, northern Norway in 1978–1980, were performed to further our understanding of the asteroids' reproductive biology. Fatty acid compositions were determined in phospholipids, triacylglycerols and alkyldiacylglycerols isolated from ovaries of frozen C. crispatus. The major polyunsaturates in phospholipids were 20:4(n-6) followed by 20:5(n-3). Both the triacylglycerols and alkyldiacylglycerols were relatively deficient in polyunsaturates but had 20:1(n-13) and 18:1(n-7) as major components. Both these liqid classes had additionally 15% of their fatty acids as a variety of odd-numbered and branched-chain fatty acids. The fatty acid composition of neutral glycerides, largely alkyldiacylglycerols, from heat-dried ovaries of C. crispatus was not materially different from that of alkyldiacylglycerols isolated from the ovaries of frozen individuals. The fatty acid composition of neutral glycerides, largely alkyldiacylglycerols, from heat-dried ovaries of P. militaris was similar to that for C. crispatus in that 20:1(n-13) and 18:1(n-7) were major components, and odd-numbered together with branched-chain fatty acids accounted for about 15% of the total fatty acids. The fatty acid composition of neutral glycerides, consisting of equal amounts of triacylglycerols and alkyldiacylglycerols, from heat-dried ovaries of A. lincki differed from those of the previous two species in that 20:1(n-9) and 18:1(n-9) were major components and odd-numbered together with branched-chain fatty acids accounted for less than 5% of the total fatty acids. The results are discussed mainly in terms of lipid biosynthetic mechanisms within the asteroids and the interplay between internal biosynthetic activities and dietary fatty acids, particularly those from bacterial sources, is considered.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    European journal of applied physiology 36 (1977), S. 101-106 
    ISSN: 1439-6327
    Keywords: Catecholamines ; Epinephrine ; Norepinephrine ; Luteinizing hormone ; Thyroid-stimulating hormone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Eight men were studied during graded (47, 77 and 100% of maximal oxygen uptake) and prolonged (76%) exhaustive treadmill running. Plasma catecholamine levels increased progressively with intensity and duration of exercise. Serum concentrations of thyroid-stimulating hormone (TSH) increased with increasing work loads and were 107 (58–243)% (P〈0.001) above resting values after maximal work. Thyroxine, triiodothyronine and luteinizing hormone in serum never changed significantly. While a small increase in testosterone concentrations (13 [1–24]%) after maximal exercise probably could be explained by changes in plasma volume, a definite increase (31 [14–56]%) occurred after 40 min of prolonged exercise. During continued exercise testosterone concentrations then gradually declined. Testicular stimulation by the increased catecholamine concentrations possibly contributed to the rise in testosterone concentrations, but no evidence was found for a direct catecholamine induced increase in the activity of the thyroid gland. The exercise induced increase in TSH levels possibly explains the increased thyroid hormone secretion rate, which previously has been found in individuals participating in physical training programs.
    Type of Medium: Electronic Resource
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