Yesterday we tweeted our weekly #FishInThePost with a special Christmas twist:


The answer was very quickly delivered by @jessica_minett, who correctly identified the answer as the European bullhead (Cottus gobio). The meaning behind our festive pun stems back to the work of Smyly (1957), who identified that bullheads fixate on a single rock known as their ‘home stone’ and return to it even after it has been moved downstream.

The European bullhead is commonly known as ‘Miller’s thumb’, which is likened to its widened head (approximately 25% greater than the width of its body – Tomlinson and Perrow, 2003). An interesting feature about the bullhead is that it can change the shade of its mottled skin in accordance with its surrounding environment, providing a very good camouflage within stones and leaf litter (Tomlinson and Perrow, 2003).


The European bullhead (Cottus gobio) – artwork Stephanie Januchowski-Hartley.

Bullheads predominantly occur in stony rivers with cool water temperatures and high oxygen levels. I personally observed this within chalk streams in Southern England, when I would be continuously retrieving and saving bullheads from my invertebrate kicknet samples collected as part of my PhD fieldwork!

Bullheads found and rescued from my invertebrate samples collected in southern England.

The bullhead is widely distributed throughout Europe, inhabiting rivers from Italy in southern Europe to Scandinavian regions in the north (Tomlinson and Perrow, 2003). Despite this, the bullhead has been included in Annex II of the European Commission’s Habitats Directive (92/43/EEC) as it was highlighted as ‘of community interest whose consideration requires the designation of special areas of conservation’ (Carter et al., 2004).

Thank you for reading our fourth edition of #FishInThePost. Our next post (and final one of 2019) will be on the 14th December! We look forward to you joining us then!


Carter, M.G., Copp, G.H. and Szomlai, V. (2004). Seasonal abundance and microhabitat use of bullhead Cottus gobio and accompanying fish species in the River Avon (Hampshire), and implications for conservation. Aquatic Conservation: Marine and Freshwater Ecosystems, 14(4). 395-412.

Smyly, W. J. P (1957). The life history of the bullhead or Miller’s thumb (Cottus gobio L.). Proceedings of the Zoological Society of London, 128, 431–453.

Tomlinson ML & Perrow MR (2003). Ecology of the Bullhead. Conserving Natura 2000 Rivers Ecology Series No. 4. English Nature, Peterborough.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s