scholarly journals Spatial and temporal variation in body mass and the blubber, muscle and visceral fat content of North Atlantic common minke whales

2020 ◽  
Vol 21 (1) ◽  
pp. 59-70
Author(s):  
Thorvaldur Gunnlaugsson
Keyword(s):  
Body Mass ◽  
North Atlantic ◽  
Visceral Fat ◽  
Energy Content ◽  
Posterior Part ◽  
The Body ◽  
Spatial And Temporal Variation ◽  
Total Body Mass ◽  
The North ◽  
Minke Whales

The exponent for predicting total body mass from length has been studied in many species and here data on common minke whales from areas in the North Atlantic is added from both Icelandic and Norwegian research catches. The exponent was found to be not significantly different from 3. In addition seasonal changes in body mass and in the parts of blubber, muscle and visceral fat are reported. The exponent for how blubber mass increases with length is lower than 3. In all cases a significant increase over the season was detected, in particular for the mature animals, and also in girth measurements, particularly at the posterior part of the body. Pregnant females had significantly more blubber than other whales. These results agree with studies on blubber thickness measurements and tissue energy content of Icelandic baleen whales and observed changes in the ecosystem around Iceland during the research period.

The specific status of the two cirratulid polychaetes, Dodecaceria fimbriata and D. caulleryi, compared by their morphology and methods of reproduction

1979 ◽  
Vol 57 (7) ◽  
pp. 1443-1451 ◽  
Author(s):  
Peter H. Gibson
Keyword(s):  
North Atlantic ◽  
The Body ◽  
Entire Body ◽  
Morphological Similarity ◽  
Type Specimens ◽  
Statistical Comparison ◽  
The North ◽  
The North Atlantic

Dodecaceria fimbriata and D. caulleryi occur on opposite sides of the north Atlantic. Because of their morphological similarity various authors have suggested that they may be the same species. Both reproduce by asexual fragmentation as atokes and then sexually as epitokes. The sizes of the entire body or regions of the body of three types of individual and two types of fragment produced asexually by each species were compared statistically. The numbers of one of the types of fragment were also compared. The result of this statistical comparison and the similarity in the methods of reproduction suggest that the species are the same. The type specimens for the atokes of the two species do not exist and therefore could not be compared. However, comparable specimens sampled from both sides of the Atlantic were found to be morphologically identical. On the basis of the quantitative and qualitative findings the two species are the same and therefore D. caulleryi should be called D. fimbriata.

scholarly journals Changes in blood testosterone and progesterone concentrations of the North Atlantic minke whale (Balaenoptera acutorostrata) during the feeding season

2004 ◽  
Vol 61 (2) ◽  
pp. 230-237 ◽  
Author(s):  
Matthías Kjeld ◽  
Árni Alfredsson ◽  
Örn Ólafsson ◽  
Morten Tryland ◽  
Ivar Christensen ◽  
...  
Keyword(s):  
Frequency Distribution ◽  
North Atlantic ◽  
Minke Whale ◽  
Balaenoptera Acutorostrata ◽  
Hunting Season ◽  
P Values ◽  
The North ◽  
Minke Whales ◽  
The North Atlantic ◽  
Cyclic Changes

An opportunity to study seasonal changes of sex hormones in the North Atlantic minke whale (common minke whale, Balaenoptera acutorostrata) arose when we obtained access to fresh postmortem blood samples from 104 females and 83 males. The whales were caught in the North Atlantic during May–September 1992–1995. Serum progesterone (P) and testosterone (T) concentrations were measured and compared with anatomical data. The frequency distribution of female serum P values showed two clusters, one consisting mainly of immature animals and the second of pregnant ones, with mean serum values of about 0.49 ± 0.04 (SE) and 44.2 ± 2.84 nmol·L–1, respectively. The frequency distribution of male serum T did not show any group-specific distribution during the hunting season. The mean serum T value for the males was 0.63 ± 0.13 nmol·L–1. Contrary to earlier reports on the Antarctic minke whale (Balaenoptera bonaerensis), serum T values rose during the hunting season in mature males (p < 0.0001). Serum P values in immature females increased during the season (p = 0.015). This increase agrees with the predominantly annual reproduction cycle of minke whales. Blood sex hormone measurements seem to be useful for detecting cyclic changes and pregnancy of minke whales.

scholarly journals Age and Growth in Phocoena Phocoena Linnaeus, 1758 (Cetacea, Odontoceti) from the North Sea

1978 ◽  
Vol 48 (1) ◽  
pp. 16-28 ◽  
Author(s):  
W.L. van Utrecht
Keyword(s):  
North Sea ◽  
Posterior Part ◽  
The Body ◽  
Age And Growth ◽  
Body Measurements ◽  
Lower Growth ◽  
The North ◽  
The North Sea ◽  
Lower Growth Rate ◽  
The Mean

Data and material are collected from 106 Harbour Porpoises (P. phocoena) from the southern part of the North Sea. All animals are accidentally caught or found stranded. The greatest length for males in the sample is 151 cm, for females 186 cm. For detailed analysis of body measurements, 30 males and 37 females are selected, while from 20 males and 34 females teeth are used for age analysis. The analysis of the body measurements shows sexual dimorphism in the anterior and posterior part of the back, in the flukes and flippers and in the position of the genital slit. The maximum number of dentinal layers found in the teeth is 12. Males attain sexual maturity after the deposition of 5 dentinal layers, females when 6 layers are formed, at a body length of about 135 cm and 150 cm, respectively. Some evidence is found that the population of P. phocoena from the North Sea has a lower growth rate than the population from Canadian waters. The gestation period is estimated to be eleven months, the peak of the birth period being in June. The animals are born at a length varying between 67 cm to 80 cm. Growth of the visceral organs is isogonic. The mean weight of the organs is greater in females than in males.

scholarly journals Atmospheric teleconnection patterns and eddy kinetic energy content: wavelet analysis

2004 ◽  
Vol 11 (3) ◽  
pp. 295-301 ◽  
Author(s):  
V. N. Khokhlov ◽  
A. V. Glushkov ◽  
I. A. Tsenenko
Keyword(s):  
Kinetic Energy ◽  
North Atlantic ◽  
Energy Content ◽  
Southern Oscillation ◽  
Eddy Kinetic Energy ◽  
The North ◽  
The North Atlantic ◽  
The Impact ◽  
The Relationship

Abstract. In this paper, we employ a non-decimated wavelet decomposition to analyse long-term variations of the teleconnection pattern monthly indices (the North Atlantic Oscillation and the Southern Oscillation) and the relationship of these variations with eddy kinetic energy contents (KE) in the atmosphere of mid-latitudes and tropics. Major advantage of using this tool is to isolate short- and long-term components of fluctuations. Such analysis allows revealing basic periodic behaviours for the North Atlantic Oscillations (NAO) indices such as the 4-8-year and the natural change of dominant phase. The main results can be posed as follows. First, if the phases of North Atlantic and Southern Oscillations vary synchronously with the 4-8-year period then the relationship between the variations of the NAO indices and the KE contents is the most appreciable. Second, if the NAO phase tends to abrupt changes then the impact of these variations on the eddy kinetic energy contents in both mid-latitudes and tropics is more significant than for the durational dominance of certain phase.

Toxaphene in minke whales (Balaenoptera acutorostrata) from the North Atlantic

2008 ◽  
Vol 153 (1) ◽  
pp. 71-83 ◽  
Author(s):  
B. Gouteux ◽  
D.C.G. Muir ◽  
S. Backus ◽  
E.W. Born ◽  
R. Dietz ◽  
...  
Keyword(s):  
North Atlantic ◽  
Balaenoptera Acutorostrata ◽  
The North ◽  
Minke Whales ◽  
The North Atlantic

Fecundity, atresia, and spawning strategies of Atlantic herring (Clupea harengus)

2009 ◽  
Vol 66 (12) ◽  
pp. 2130-2141 ◽  
Author(s):  
Cindy J.G. van Damme ◽  
Mark Dickey-Collas ◽  
Adriaan D. Rijnsdorp ◽  
Olav S. Kjesbu
Keyword(s):  
Energy Content ◽  
The Body ◽  
Clupea Harengus ◽  
Oocyte Development ◽  
Atlantic Herring ◽  
Down Regulation ◽  
The North ◽  
Spawning Areas ◽  
High Level ◽  
Autumn And Winter

Atlantic herring ( Clupea harengus ) have contrasting spawning strategies, with apparently genetically similar fish “choosing” different spawning seasons, different egg sizes, and different spawning areas. In the North Sea, both autumn- and winter-spawning herring share the same summer feeding area but have different spawning areas. Females of both spawning types start their oocyte development in April–May. Oocyte development is influenced by the body energy content; during the maturation cycle, fecundity is down-regulated through atresia in relation to the actual body condition. Hence, fecundity estimates must account for the relative time of sampling. The down-regulation over the whole maturation period is approximately 20% in autumn- and 50% in winter-spawning herring. The development of the oocytes is the same for both spawning strategies until autumn when autumn spawners spawn a larger number of small eggs. In winter spawners, oocyte development and down-regulation of fecundity continues, resulting in larger eggs and lower number spawned. In theory, autumn and winter spawners could therefore switch spawning strategies, indicating a high level of reproductive plasticity.

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