User:Jboogaar

Jen Boogaards: UWO Physiology Seminar

Articles needing attention

Smoltification: Though smoltification is a crucial aspect of the salmonid life history, both the salmonidae wikipedia page and the salmon page lack reference to this important and fascinating physiological event. Adding a discussion regarding the process of smoltification to these pages would greatly improve understanding of the salmonid lifecycle and the unique processes involved. Alternatively, as the topic of smoltification is a complex and detailed process, a new wikipedia page discussing this event would be beneficial.

Crucian carp: The crucian carp is a classic example of an animal able to tolerate hypoxic, even anoxic conditions. However, the crucian carp wikipedia page fails to even mention this remarkable ability. Elaborating on the physiological capabilities of the carp would certainly enhance the information provided about this species.

Incubation: Incubation is an important process in avian development. However, the wikipedia page describing incubation does not mention the importance of maintaining certain incubation temperatures, though several recent papers show that incubation temperature is variable within species and these discrepancies can influence offspring characteristics. I believe updating this section of wikipedia to include the consequences of incubation temperature would benefit this page.

Smoltification is great and of general interest to many

Wikipedia update: Salmonidae

Article to review: Salmonidae

Critique

Wikipedia’s Salmonidae page presents basic information regarding the Salmonidae family, including a brief morphological description, an evolutionary history, and an outline of the Salmonidae scientific classification system. Importantly however, physiological characteristics of this family are entirely omitted. For example, although the page presents the idea that several Salmonid species are anadromous, breeding in freshwater and maturing in the marine environment, the page does not detail the physiological characteristics of this lifestyle. Specifically, one aspect of the Salmonid anadromous life-history absent in this discussion, and to my knowledge within Wikipedia as a whole, is the endocrine-driven process of smoltification, whereby physiological, morphological, biochemical, and behavioural changes function to prepare freshwater life stages for the challenges of a marine lifestyle. This oversight ultimately leaves Wikipedia’s Salmonidae page informatively deficient as smoltification is an indispensible component of anadromy within this family. Indeed, the crucial nature of this developmental event is highlighted by observations that in the absence of smoltification, anadromous Salmonids poorly tolerate marine conditions and thus migration from freshwater breeding habitats to marine growth environments.

An array of research has been dedicated to elucidating the physiological manipulations occurring during smoltification, as well as the environmental and physiological cues directing this process, thereby providing a substantial base of literature upon which to update Wikipedia. Given the imperative nature of smoltification for salmonid anadromy, including a brief overview of the changes occurring during, and the mechanisms controlling, this process would substantially enhance the completeness of the information provided on Wikipedia regarding the Salmonidae family. Specifically, in an initial introduction to smoltification, highlighting the environmental stimuli signalling the parr-smolt transformation as well as the hormonal cues regulating this process is important for establishing an understanding of the regulation of this developmental event, and thus smoltification as a whole. Moreover, as establishment of a hypo-osmoregulatory capacity is an important attribute of smoltification, including information regarding the cellular-level manipulations of the gills contributing to this physiological alteration would increase understanding of the specific processes characterizing the changes associated with smoltification. Ultimately, such an update will increase public comprehension of, and appreciation for, the physiological mechanisms that allow Salmonids to inhabit both freshwater and marine environments.

Three key references for this wikipedia update include:

1) Environmental endocrinology of salmon smoltification

In this review, Bjornsson et al. (2011) discuss several aspects of the developmental events characterizing both smoltification and post-smolt development, as well as environmental and endocrine regulation of these processes. Some key conclusions of this paper for a general introduction to smoltification in a Wikipedia update include:

• During the parr-smolt transformation, preparatory changes include increased oxygen carrying capacity; a switch from hyper-osmoregulation to hypo-osmoregulation, accomplished partly through increased salt excretion (via increased activity of transporters such as the Na+/K+-ATPase); morphological alterations (a silvering of the body); a switch from territoriality to schooling behaviour.
• Environmental cues controlling smoltification are complex, though photoperiod along with temperature appear to be particularly important.
• The parr-smolt transformation is controlled by several endocrine systems: Growth hormone and the IGF-1 system along with cortisol promote osmoregulatory manipulations, while thyroid hormones are thought to control the behavioural and morphological alterations characteristic of smoltification. Prolactin is inhibitory.
• Following downstream migration, smolts move into coastal waters and eventually, the open ocean. Entry into seawater stimulates a series of physiological changes facilitating “post-smolt” marine survival, including maintenance of or increased hypo-osmoregulatory capacity (maintenance of or increases in ion transporter levels and activity during acclimation to seawater), high growth rates, increased condition, and high energy metabolism. The growth hormone-IGF-1 system plays a key role in these changes, with thyroid hormones also involved.

Including this information in a Wikipedia update will provide a basic overview of characteristic physiological, morphological, biochemical, and behavioural changes occurring during smoltification as well as the regulation of this event, thereby facilitating a thorough introduction to this process. Moreover, this paper is a useful reference Wikipedia users could access to obtain additional information regarding smoltification, beyond Wikipedia’s general introduction.

2) Low temperature limits photoperiod control of smolting in Atlantic salmon through endocrine mechanisms

In this study, McCormick et al. (2000) investigated the interplay between photoperiod and temperature in smoltification control in Atlantic salmon, as well as the role of endocrine systems in this smoltification regulation. The relevant findings include:

• A relationship between circulating hormone levels (growth hormone, IGF-1, cortisol, and thyroid hormone (T4)) and physiological changes characteristic of smoltification (increased gill Na+/K+-ATPase activity, decreased condition) indicate the parr-smolt transformation is an endocrine-driven process.
• Smoltification is partly under the control of temperature, with warmer temperatures accelerating smoltification. Photoperiod also plays a role in smoltification regulation whereby increased day length accelerates smoltification, although temperature limits this photoperiod control. Specifically, low temperatures prevent extended day lengths from accelerating the parr-smolt transformation.
• Low temperature delays smoltificiation and limits the ability of extended photoperiods to accelerate smoltification via endocrine systems, as indicated by observations that in cool temperatures, increases in the levels of hormones associated with smoltification promotion are both delayed and dampened.

These findings are important for a thorough Wikipedia update as they informs the interaction between environmental cues for smoltification and the endocrine systems through which these cues regulate this developmental event, each of which are important for a complete understanding of this transformation.

3) Gill Na-K-2Cl cotransporter abundance and location in Atlantic salmon: effects of seawater and smolting

Pelis et al. (2001) examined the effects of smoltification and seawater acclimation on saltwater tolerance and expression of the Na-K-Cl cotransporter, which has been hypothesized to play a role in osmoregulation, in Atlantic salmon. The relevant findings for a smoltification Wikipedia update include:

• The Na-K-Cl cotransporter is found in Atlantic salmon gills, particularly within gill chloride cells, and thus is likely involved in osmoregulation.
• Expression of the Na-K-2Cl co-transporter in Atlantic salmon gills increases over the course of the parr-smolt transformation, and these increases coincide with both increases in Na-K-ATPase activity and increased saltwater tolerance. These findings indicate both a mechanistic link between the co-transporter and Na-K-ATPase, and that both of these transporters are involved in establishment of the hypo-osmoregulatory abilities observed during smoltification.
• Chloride cell number and size increase over the course of smoltification in some gill tissues, which likely contributes to increased salinity tolerance observed during smoltification.

This information would benefit a Wikipedia update as it provides an example of the cellular-level alterations responsible for the physiological changes observed during smoltification and the importance of these changes for an anadromous salmonid lifestyle, particularly salinity tolerance.