MSc Module 4: Genetics and Reproduction

Salmon smolts swimming around a submerged light

We just completed our fourth 2-week module, entitled 'Aquatic Animal Genetics and Reproduction'.  This module was the toughest one yet, but I found the material very useful and applicable.

Herve Miguad was one of the main lecturers, who covered the physiological aspects of fish reproduction, including endocrinology and environmental manipulation for the induction of spawning.  Brendan McAndrew covered the basics of genetic markers and several techniques currently used by the industry to undertake research into concepts such as selective breeding.  Then, Dave Penman lectured on sex ratio control (many farmers may only want to grow one sex of fish, as it may perform better) and chromosome sex manipulation (creating triploid fish- see my previous blog article on triploidy).  We then received a series of lectures on the major biological and practical differences of a variety of finfish hatchery operations, highlighting the ways in which technology conforms to reproductive strategy. 

This module included two field trips: one to Howietown to spawn brown trout broodstock (see my previous blog article), and the other to an Atlantic salmon smolting facility to practice a variety of industry techniques.  'Smolting' is the process that juvenile salmon go through to prepare themselves for the transition from freshwater, where they are born, to saltwater, where they will spend the majority of their lives.  At this smolt unit, owned and operated by the Institute, we practiced blood sampling and performing ultrasounds: the latter is used to determine the development stage of the gonads in large broodstock.  We also practiced inserting PIT (Passive Integrated Transponder) tags into fish: these are tiny capsules that emit a unique ten-digit number when placed next to an electronic reader.  They are inserted just underneath the skin and are used to individually identify fish for the purposes of selective breeding or the establishment of pedigree lines.

Overall, this module was difficult from an academic perspective, but the material seems integral to a comprehensive view of the industry.  The next module is ‘Aquaculture Production Systems’, and as this topic holds a much greater personal interest for me, I am very excited to see what it has in store!

Atlantic salmon smolt next to blood sampling and PIT tagging tools

Using ultrasound to look at the development of the ovaries in a broodstock brown trout