Whether it’s bullheads or bleak, many of us have a soft spot for angling’s smaller species. But how much do you really know about these remarkable little fishes? And with this being an Olympic year, which of these fishes are the fastest, toughest and weirdest of the lot? Who better to delve into their world than Angling Trust Ambassador Dr Mark Everard, author of many excellent books on fish and fishing, including recent titles on gudgeon and ruffe.

100cm Sprint: In a straight sprint, the bleak (Alburnus alburnus), below, has to pick up the Gold Medal for the fastest fish.  Bleak are sometimes evocatively known as the ‘river swallow’ for their habit of vanishing in winter and reappearing in large numbers in the spring and summer.  They can form dense shoals in rivers, eagerly flitting around near the surface to intercept spindrift and floating objects.  Catchable on dry fly or bait, I have said before that, if they grew to a few pounds, these little sprinters would be valued as our own native ‘mini-tarpon’!

Rarest Fish: No contest!  This has to be the spined loach (Cobitis elongatoides).  This small fish is characterised by a spindle-like body with a small mouth surrounded by at least three pairs of short barbels as well as a strong, retractable double-pointed spine located in a skin pouch below and in front of each eye. 

The spined loach is one of Britain’s smallest and rarest native fishes, almost entirely restricted to a few catchments in eastern England.  These fish are not highly mobile, living in dense submerged vegetation where they remain by day, emerging by night to feed on small bottom-living invertebrates as well as some vegetable matter.  They can also utilise atmospheric oxygen if oxygen levels in the water becomes depleted, coming to the surface to exchange an air bubble in their mouths.

Toughest Fish: Although spined loach can breathe air in tough times, the Gold Medal for the hardiest fish surely has to go to the ‘well hard’ three-spined stickleback (Gasterosteus aculeatus), below.  It is not just the modification of the front dorsal fin into three strong spines, giving the fish its common name, nor even the scutes (strong armour-plated scales on the flanks in come populations) that rank this fish as the hardiest. 

Also coming into contention is the ability of this fish not only to move into estuaries but even into fully saline coastal waters, some populations overwintering in marine water before re-entering rivers in spring when spate flows abate.  Three-spined sticklebacks can also tolerate often quite significant pollution, in which conditions they can form dense shoals in the absence of competition from other fishes.

Extreme eating: Gold Medal for the greediest fish probably has to go to the ruffe (Gymnocephalus cernua).  As many an angler knows, this little predator tends to inhale worms, maggots, bloodworms or other baits as voraciously as a student at a free buffet.  A quick strike is vital to avert deep hooking.  Miniature thugs they might be, but here is something heart-warming about these little ruffians, as they just radiate spiky attitude!      

However, another close contender and our silver medallist in the greediest mini-species category has to go to the bullhead (Cottus gobio).  This is not merely for what this cryptic predator eats, but because the head and mouth are so big compared to the small body that tapers off behind the gills.

Best Camouflage: Many smaller fish species are good at hiding, but let’s award the Gold Medal for the best at hiding to the stone loach (Barbatula barbatula).  This elongated, scale-less fish with a small mouth surrounded by at least three pairs of elongated barbels is secretive by day, emerging to feed primarily in the dark on a range of small invertebrates. 

Adult fish are largely solitary, though favourable refuges may harbour other stone loaches as well as bullheads.  Arguably, the spined loach is as, or perhaps even more, secretive.  But it already has a gong for its rarity, so I am sure it would be happy to allow this medal to go to this other fish, despite the fact that stone loach and spined loach belong to different loach families.

Best Fighter: Gold Medal for the hardest fighter is a tough call, but I think this gong has to go to the ever-popular gudgeon (Gobio gobio), pictured below.  There is no doubt that a gudgeon can put up a strong account of itself on light tackle.  Also, as dusk sets in, many is the time I have had a ‘four foot twitch’ when barbel fishing only to find that the culprit is a tiny gudgeon!  Other mini-species may have a competing claim for this award, but as a judge I am emotionally swayed by the fact that this is ‘the angler’s favourite tiddler’, bringing a smile to the faces of anglers of all ages.

Most Promiscuous Fish! Ok, so this isn’t even close to an Olympic event (just imagine if it was!), but the Gold Medal for the most promiscuous mini-fish is a tie between two of our less-welcome visitors.  The positively spawny topmouth gudgeon (Pseudorasbora parva, also known as the clicker barb) and sunbleak (Leucaspius delineates, also known as the motherless minnow) are not native to British waters but have become established here.  They cause problems as they are so prolific, maturing after only a year and producing multiple broods of eggs annually, with some guarding of the eggs by male fish.  Both species can not only explode in numbers, but also predate the eggs and fry of other species, effectively preventing regeneration of native fish populations.

Power Lifing (Ultra Feather Weight Category): The Gold Medal for weight-lifting has to go to the fish with the most muscles, the bitterling, if we are permitted a small spelling error.  Though not native, bitterling (actually several small species of the genus Rhodeus) have become naturalised for at least a century in some still and sluggish waters in south Lancashire, Cheshire, parts of Shropshire and some of the Great Ouse catchment.

 So, what is so muscular about these fish?  Well, actually it should be spelled ‘musselar’, because freshwater mussels play a key role in the bitterling’s unique life cycle.  Male bitterling become colourful in spring and select a suitable freshwater mussel, to which they attract female fish that grow a fleshy ovipositor (egg-tube) extending from their genital opening.  The female bitterling inserts her ovipositor into the mussel’s feeding tube, sticking 1 or 2 eggs onto the gills in the space between the mussel’s shells, the male bitterling then fertilising them by shedding his milt near the mussel.  The eggs and hatching larvae remain protected from predators within the mussel’s mantle cavity, before metamorphosing into fry that leave the sanctuary of the host mussel.

Most Curious Fish: The Gold Medal for the most curious mini-species, endearing itself to all and sundry from kids right up to those at the dustier end of the age scale, surely has to go to the minnow (Phoxinus phoxinus) that, for all its bite-sized appeal to predators, is irrepressibly curious.  Just wiggle your toes in a summer river and you will attract a hoard of them eager to nibble these strange things!

Smallest Fish: The Gold Medal award for the smallest fish goes to the ten-spined stickleback (Pungitius pungitius, also known as the Nine-spined Stickleback).  Although that contest is nearly a dead heat with the spined loach, the spined loach already has an award so the ten-spined stickleback deserves its day at the races!

Most Neglected Fish: And, finally, the Gold Medal for the most neglected fish goes to… the silver bream (Blicca bjoerkna).  It is amazing how many experienced anglers have not heard of silver bream, claim never to have seen one, or tell me they are unable or not confident in their identification.  I suspect that many silver bream are caught and misidentified as ‘skimmers’ (small common bream), roach-bream hybrids or just returned without further thought.  I have to say I have developed quite an affection for this fish that, though not a giant, leads me to bend the competition rules a bit as, in reality, silver bream are not quite small enough to qualify as a mini-species!

I am sure you may have your own list of contenders but, as we look ahead to the Tokyo Olympics (I am old enough to remember them when they were on in 1964), let’s not forget that we have prize-winners of our own in the waters right here at home!

Catch more from Dr Mark Everard!

The author of various excellent books on fish, fishing and ecology, you can read more from Mark at www.markeverard.uwclub.net Recent highlights include his collectible books Gudgeon: The Angler’s Favourite Tiddler, Ruffe: The Spiky Little Freshwater Ruffian, as well as his fascinating work The Complex Lives of British Freshwater Fishes. You can also find Mark’s “Dr Redfin” specialist roach fishing rods, at the same website.