Freshwater fish - ecological niches (1 Viewer)

[Carless]

Today I got the chance to try lifting a few rocks in the River Biam. I was curious to see whether there were Miller's thumbs in it. So I did, but found a different fish. At first I thought it was a stone loach, but it just sat there still, in full view. Not stone loach behaviour in the least. While I prefer to limit the amount I disturb wildlife to a minimum, I was very surprised to see what I thought was a stone loach in an unexpected place. So I caught it in my hands, with absolute ease. I made sure I kept a supply in water there, and returned it to the water ASAP, and counted the barbels for an ID. 4 barbels, versus 2 for gudgeon, and 6 for stone loach, and I presume other loaches though I'm unlikely to see any of those.

However, I'm starting to lose confidence that I've been identifying juvenile barbel correctly. All photos I've seen of juvenile barbel online look nothing like what I've seen.

while what I saw today was very different. Some pictures of stone loaches look so much closer to what I saw today, such as http://www.dave-guest.pwp.blueyonder.co.uk/pics/B_barbatula.jpg

And if these fish aren't barbel, I wonder what they are. While, as I said, I prefer to be non-interventionist concerning observing wildlife. But I must admit that I'm strongly tempted to obtain a proper clear viewing cell, catch one (very easy), and get some good photos. If they were loaches that would say a lot about their distribution and the waters around here. But surely given the places I've found these fish, and the stone loaches' absence from polluted waters.

In any case, I was surprised to find a fish other than loaches or miller's thumbs under rocks. Perhaps there's a degree of inter-species competition for hiding places. And the absence of miller's thumbs has opened up a niche for barbels to take over. But barbels hiding under rocks? I'm not sure they do that.

Is anyone here familiar with what barbel look like up to say three inches long? I'm confused.

 

[John P]

Is anyone here familiar with what barbel look like up to say three inches long? I'm confused.

They look pretty much like the one in the EA pic you posted.

I fish for Barbel and spend quite a bit of time watching them as well, lurking under stones is not typical behaviour even for 2"-3" fish.

They are far more likely to be on open gravel with a good flow over it, one place where I can watch dozens of baby barbel is just above a weir, they will be lined up almost looking as though they have their pectorals hooked over the edge of the concrete apron for stability, but they are quite capable even at that size of coping with the strong flow there. I doubt if I could stand up in it.

As to what your fish was I really don't know, there is more than one loach in the UK, we have Stone Loach and Spined Loach, I think there are even more varieties in Europe which would be capable of surviving in British rivers, could be a freebie from someones aquarium.

 

[Carless]

They look pretty much like the one in the EA pic you posted.

I fish for Barbel and spend quite a bit of time watching them as well, lurking under stones is not typical behaviour even for 2"-3" fish.

They are far more likely to be on open gravel with a good flow over it, one place where I can watch dozens of baby barbel is just above a weir, they will be lined up almost looking as though they have their pectorals hooked over the edge of the concrete apron for stability, but they are quite capable even at that size of coping with the strong flow there. I doubt if I could stand up in it.

As to what your fish was I really don't know, there is more than one loach in the UK, we have Stone Loach and Spined Loach, I think there are even more varieties in Europe which would be capable of surviving in British rivers, could be a freebie from someones aquarium.

Yes, I was thinking that hiding under rocks was a bit unlikely. Having only had the fish in my cupped hands, maybe I miscounted the barbels.

Thanks. I think I'd recognise a spined loach. I've seen them on sale in aquarium shops, and would like to believe that I would recognise the tyre-track patterns on the side.

Spined loach are reported as "uncommon" in the river Soar (due to Industrial Revolution age engineering, the Rivers Soar and Biam are pretty much one and the same), while Stone loach are reported as "common (rivers and streams)".

(http://www.leics.gov.uk/index/commu...eys_fishfinders/chi_leicestershire_fishes.htm)

I also thought that the spined loach typically buries itself in mud, rather than under stones. So if it is a loach, I'd guess that it's a stone loach. But I've seen much larger examples (say 3-4") in the river Soar, including one that very helpfully sat still on the substrate in a shallow and clear part of the river right next to a path. I thought I'd counted the barbels correctly, and there were four. And that the scales weren't particularly small. But maybe these aren't the same fish. I.e. I may be confusing myself by thinking of two different species as one and trying to find a single species that fits all the evidence. Since the River Biam takes water from the Soar, and the "Upper Soar" is one of the locations listed for the Spined Loach, so that is a possible. But I think unlikely.

I originally mistook these fish for gudgeon. After reading that juvenile barbel are often mistaken for gudgeon, and counting the barbels, I presumed that they were juvenile barbel. If they aren't, then that would help explain why the juveniles seem incredibly common, but I have never seen an adult.

If it were an escape from an aquarium, then I think given the large numbers and wide range of these fish (we've also seen them in the Grand Union canal), I would have come across reports of them as an invader.

Thanks for the pointers. I think that I'm going to catch one and have a look at it in a proper viewing container. Before carefully returning it to the river of course.

Edit: The plot thickens. The stone loach isn't reported as being present in canals, but the uncommon spined loach is. And I've seen these fish in the canal.

 

[Carless]

I have since found this photo.

http://www.hull.ac.uk/cichlids/images/loach.jpg

which is a photo from the top, an angle I'm much more used to seeing.

The barbels on this fish stick out forward, rather than straight down as in the juvenile Barbel. The fish I see in the Biam, the Soar, and the Grand Union Canal all have forward pointing barbels.

I would have thought the Soar and the canal would have been too polluted for Stone Loach, which I've seen quoted as a very good clean water indicator, more so than Trout. So the water may be cleaner than I thought.

Apologies for spamming the forum with repeated postings.

 

[John P]

There's what seems to be some good info here regarding distribution and behaviour of Spined Loach in the UK.

 

[Carless]

There's what seems to be some good info here regarding distribution and behaviour of Spined Loach in the UK.

The river has been in flood since who knows when. Which is a pity as when it clears out I was planning to snorkel up a region of it to see what I could see.

However, last Saturday, even though the river was in flood, I saw a fish in the shallows that I am quite sure was a spined loach. I don't know for sure if the other fish under the stones were spined or stone loach. I will find out if we get a period of good weather so that the river falls and clears.

As a not-too-serious comment, I haven't seen a spined loach from the top before. It's somehow reassuring that it's a weird looking wormy thing from that angle with a funny head. The UK has too many fish that are stereotypical carp shape with red fins. Great to see something more unusual.

 

[Carless]

The river has been in flood since who knows when. Which is a pity as when it clears out I was planning to snorkel up a region of it to see what I could see.

It's clear now. I had a sort of quick dip in a large, clear, pool. The view was fantastic. The water wasn't quite crystal clear, but I could see a fair way. Unfortunately I didn't have a snorkel so air exiting my nose obscured the view a bit (I'm too used to swimming and had quite some difficulty remembering to hold my breath). I didn't see more than minnows, gudgeon, roach (probably), and a miller's thumb (I lifted a rock). I haven't had a proper side view before! There are still other fish to see there.

The minnows were great fun. They seemed to have no fear of me providing I wasn't moving too fast. On the contrary, they seemed to think that I looked like something good to eat, and I could feel frequent tickling sensations as they attacked me. At one time I had my hands in front of me and the minnows were swimming around my hands and between my fingers.

I have snorkelled on the Great Barrier Reef, Australia. OK, so it wasn't as impressive as that, but as it was free, it compares quite well on a value for money basis.

I have seen kingfishers working that pool. Now, if I was to see a kingfisher from an underwater view, that would be really something.

I'm glad I was wearing water shoes though as I found some really nasty glass on the river bed. I removed it to a rubbish bin.

 

[matt green]

Nice to read of your latest endeavors carless.

Done a little fish watching myself this afternoon at the university of east anglia broad and river, was very pleased at the sight of a small Pike!!

Only about one foot long, it was absolutely beautiful with it's markings reflecting in the sunlight.

if you can make it out from the picture you're doing very well indeed

Matt

 

[rozinante]

Nice to read of your latest endeavors carless.

Done a little fish watching myself this afternoon at the university of east anglia broad and river, was very pleased at the sight of a small Pike!!

Only about one foot long, it was absolutely beautiful with it's markings reflecting in the sunlight.

if you can make it out from the picture you're doing very well indeed

Matt

No problem here Matt, its a sight my eyes are well practiced at seeing. The matching of the surface reflections in the fishes colouring is perfect.

Here, I have done a little post processing to help anyone who might be having difficulty picking it out :-

 

[alan_rymer]

No problem here Matt, its a sight my eyes are well practiced at seeing. The matching of the surface reflections in the fishes colouring is perfect.

Here, I have done a little post processing to help anyone who might be having difficulty picking it out :-

Well I'm not fooled. The photo of Matts fish looks more like a Wrasse!. Obviously taken in tidal waters

 

[Keith Reeder]

Actually, pike can do rather well in brackish water: there are some very big pike around the Baltic whose diet includes live herring!

 

[alan_rymer]

Actually, pike can do rather well in brackish water: there are some very big pike around the Baltic whose diet includes live herring!

Yup

Used to kmow a Swede who owned an island in the archipeligo. Fished in summer off his boat for Pike & Perch and in winter, Ice fished for the same!.

 

[Carless]

I've seen pike in the river Soar and the Grand Union Canal. Nothing as small as one foot long though. I haven't had the chance to have a better look in the river mentioned as the weather turned bad and the river is high and murky again. For such a small river, it can really turn into a raging torrent when in spate. I've been swimming for swimming's sake in a few other lakes and rivers since then, but all had effectively zero visibility. My son and I went "pond dipping" in Rothley brook, which was clear, but too shallow to swim. We didn't see anything new or unusual.