On Thursday we tweeted this week’s #FishInThePost question: ‘Me being one of Wales’ smaller freshwater fishes, is it not impressive that I produce up to 1,000 eggs in a breeding season? Which Welsh freshwater fish am I?


Winning guess by Pepijn for this week’s #FishInThePost! 

We had several great guesses, commentary, and puns about which species we were referring to in this week’s #FishInThePost. I did share a cheeky clue on Twitter this morning, ‘lemme know’ which fish is this week’s #FishInThePost. Cory Brant picked up on that nicely; indeed let Minnow is a solid fish pun. However, the prize goes to @PKtje who first guessed this week’s fish correctly, which is Minnow! Well done @PKtje we are sending you a Minnow in the post! 


Minnow (Phoxinus phoxinus) aka Eurasian Minnow, Common Minnow.

Minnows weigh in at only 8-16 grams, but they are the unsung heroes of our rivers! Like many other fishes, male Minnows transform into emeralds and golds in breeding season, along with white nodules over their heads and fins. Minnows are also masters of shoaling; the behaviour is ever-present from three to four weeks after their emergence as young. This shoaling behaviour along with their small size and ubiquity in freshwater systems in Europe means that the species behaviour has been fairly well studied


Minnows shoaling. Photo by Carlo Morelli; shared under Creative Commons Attribution-Share Alike 3.0 Unported

Minnows range widely across Eurasia, from Wales and England to the Garonne River in France and across to eastern Siberia. This could be why there are also many common names for Minnow, making their scientific name Phoxinus phoxinus a useful way of confirming one is speaking of the same species as another. While Minnows range widely across Europe, and are native to Wales, the species is regarded as introduced in both Scotland and Ireland. Abundant throughout much of Europe, cold [abundant in the UK], well oxygenated, waters are preferred by Minnows. They also prefer clean gravel for spawning, which they do via upstream migrations from April to June, and coarse substrate for hiding. 

Of all the fish in Welsh waters, you are highly likely to come across a shoaling group of Minnows on a river or lake edge. Keep an eye out in spring and summer for small groups of fishes along the fringes of our waterways, you might just spot some Minnows! A key characteristic of Minnows is the elongated blotches along the fishes’ bodies (like in the drawing and image above). 

We look forward to spring, getting out along the River Tawe, and sharing pictures and stories of any fishes and other wildlife that we come across with you all here on the blog! Thank you to everyone who joined in this week’s #FishInThePost! Next week Tara Cater is sharing with us about research ethics, because she has been working on our own application for field work. The next #FishInThePost is in two weeks; see you then! 

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