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What environmental cues do salmon use to initiate smoltification?

What environmental cues do salmon use to initiate smoltification?

Photoperiod and temperature are critical environmental cues for smolt development, and their relative importance will be critical in determining responses to future climate change.

How long does smoltification take?

Yearlings are normally in the process of smoltification as they migrate downstream. This process of physiological change begins 20 to 30 days after river migration begins (Beeman et al. 1990).

What is desmoltification?

Desmoltification is generally viewed as a loss of important preparatory adaptations to marine life, including loss of hypo-osmoregulatory ability, critical metabolic adaptations, behavioural changes (e.g. re-establishment of positive rheotaxis) and major endocrine changes.

Why is smoltification important?

Successful smoltification is an essential prerequisite to marine survival of both salmon and trout. Thus in an Irish context the protection, conservation and management of these species will rely on identifying and addressing anything potentially perturbing the smoltification process.

What is Parr smolt transformation?

Smoltification (also known as Parr-Smolt transformation) is a complex series of physiological changes where young salmonid fish adapt from living in fresh water to living in seawater.

What is the salmon life cycle?

As compared to a typical freshwater or marine fish, the life cycle of salmons is very interesting. It comprises six stages: egg, alevin, fry, parr, smolt, and adult. In simple words, they are born and die in freshwater rivers, but remain in the sea till the onset of adult stage.

How heavy is a smolt?

The average size of the smolts ranged from 70 to 215 g (Table 1). … transported in commercial well boats were monitored in Norway and Scotland between spring and summer 2002 (Tables 1 and 2).

How old is a smolt?

3.7 years
Smolts have a mean age of 3.7 years and a fork length of 12.0 cm, relatively small for most salmon stocks of the region (Power 1981).

What color is a smolt?

Coincident with their downstream migration in spring, the vertical bars on their sides known as parr marks are lost, and smolts become a bright silver color with dark fin margins.

What is Smoltification and why is it important as salmon transition from freshwater to saltwater?

Salmon are anadromous fish that undergo a physiological process termed smoltification. This process helps juvenile fish living in freshwater adapt to their adult life in seawater (Supplementary Figure S1). Immediately after smoltification, the fish are transferred to seawater.

What happens in smoltification?

Physiological changes during smoltification include modified body shape, increased skin reflectance (the measure of the proportion of light or other radiation striking a surface which is reflected off it.), and increased Na+/K+-ATPase in the gills. A number of mechanisms assist with osmoregulation.

What is smolt mean?

: a young salmon or sea trout about two years old that is at the stage of development when it assumes the silvery color of the adult and is ready to migrate to the sea.

What is the biological mechanism of salmon smoltification?

Smoltification, or parr–smolt transformation, is the biological mechanism which allows the anadromous salmonids to make use of both the FW and SW environments during their spectacular lifecycle (Hoar, 1976; Folmar and Dickhoff, 1980, Barron, 1986, McCormick and Saunders, 1987, Stefansson et al., 2008, McCormick, 2009).

When does smoltification occur in a river or Lake?

Under natural conditions in rivers and lakes, smoltification is a seasonal process usually occurring in late spring. Due to its similarity to metamorphosis coupled. However, detailed studies have revealed that smoltification is a synchronisation

How are temperature differences indicated in a smoltification?

Values are given as means (sem, n = 12). Significant differences among temperatures are indicated by different letters (p < 0.05). The asterisk indicates significant differences among strains (p < 0.05). From Handeland et al. (2004). … … Content may be subject to copyright. Content may be subject to copyright.