How to tell the diffs between Smallmouth vs Largemouth

[Gerrit Viljoen]

Yesterday me and Troutmaster attended a clinic on the Vaal hosted by Ian Couryer and one of the guests was Gordon.Sorry I forget his surname now but he's from JHB University and are currently in charge of the yellow tagging program being conducted at Wag 'n Bietjie just to name one place.

Good news is that very soon all their info and research will be posted online and believe you me some very very interesting information came out so far.

Right moving on to the juicy stuff how tell the difference?

As I said in the Middelbek thread at a very young age you cannot tell the difference between the two fish.Well I happen to be 100% correct.

Under 100mm or there about there is NO WAY in telling the difference by just looking at the fish.Only once the they grow larger than 100mm or there about can we ascertain the ID by means of a very easy and simple procedure/test.

There is ONLY one visible difference to determine it's ID but you need to do some measurements.I reckon after a while you'll be able to do it by just looking at it but if you're not sure rather measure it,especially on smaller fish.Bigger fish is pretty straight forward.

Measure what?

1.You need to measure the distance from the snout to directly above the eye (looking down at the fish) or snout to the middle of the eye(looking at it sideways)= 1st measurement.For example let's say it's 3cm.

2.Distance from the eye to the beginning of the Pre Periculum plate.Let's say this distance is 5cm.

With the above measurement the answer is Largemouth.

If the 2 measurements are turned around ie the snout to eye length was 5cm and the distance from eye to beginning of the pre periculum plate is 3cm your answer would be smallmouth.

No if's and but's here folks,forget about all the other "ek weet nie eintlik nie" theories,this is 100% correct,fact!!

The only scifi name and spelling I'm not sure of is the name PRE PERICULUM PLATE.

You scifi lads can correct me on that one.

Attached is a pic to demonstrate.

[Troep]

Interesting Gerrit!! Very!!

[Scythe]

Very interresting.

Catch many SM < 100mm ?

[WazzyP]

Nice post...

So how exactly does the Natal Scallie fit in?

[jock0]

I think you could use the location with regards to natal scalies? I'm not aware of too many rivers where they're found together with SM and LM yellows

[WazzyP]

Was more wondering if they're an actual yellowfish species? Or just something similar?

[Gerrit Viljoen]

Nice post...

So how exactly does the Natal Scallie fit in?

The chap mentioned them,for the love of chop 'n dop I can't recall anything worthwhile.

[Andre]

The scalie, is one of the nine yellowfish species in SA. It is found in the natal river systems only, and does not occur naturally in the Vaal/Orange system which is the natural system of the large and smallmouth yellow.

[Andre]

The true yellowfish are:
Orange-Vaal smallmouth yellowfish - Labeobarbus aeneus
Orange-Vaal largemouth yellowfish - Labeobarbus kimberleyensis
Clanwilliam yellowfish - Labeobarbus. capensis
Natal yellowfish (scaly) - Labeobarbus natalensis
Bushveld smallscale yellowfish - Labeobarbus polylepis
Lowveld largescale yellowfish - Labeobarbus marquensis

The three related species are:
Clanwilliam sawfin - Barbus serra
Berg-Breede River -whitefish - Barbus andrewi
Bushveld papermouth - Barbus rapax.

(copied from the FOSAF site)
http://www.fosaf.co.za/ywg.php

[WazzyP]

Fantastic...thanks Andre