Fish observations

Opportunities for fish observations might be unexpected. Perhaps a die-off caused by cold water or pollution, or one might encounter stranded fish after a storm. Detailed descriptions of such events are valuable.

1. Dead specimens

With dead specimens, or fish that are to be sacrificed anyway (like an angler's catch), it would be worthwhile for the sake of identification purposes on iSpot to observe a few guidelines when taking photographs:

SPREAD THE FINS (and barbels, if present)
The relative size and position of fins are important for identification. If the dorsal and anal fin spines and rays can be discerned in the photographs, identification will be greatly facilitated.

SHOOT FROM THE SIDE
Though photographs from all angles will help, the most important one will be the shot from the side, so that the following can be seen:

-Scale count along the lateral line.

-The ratio of head length to body depth.

-The size, shape and positioning of the fins (and the spine and ray counts as mentioned)

-A vertical scale count across the deepest part of the body.

-Eye orbit diameter relative to other body parts

We also value catch records. So when fishing, remember many fish fade quickly after death: try and get at least one picture while it is still alive.

2. Live specimens

Fish shouldn't be injured or stressed for observation purposes.
Catch and release angling is a growing sport, but anglers should know that improper handling could lead to the death of fish some time after their release. Bruising and scale damage could lead to a variety of lethal infections. So could contact with dry or warm surfaces. A fish dropped unto dry sand has a slim chance of survival, even if it swims off when released.

Many fish species can be held by the lower jaw (dentary), using thumb and forefinger while the other hand supports the body. Beware of sharp teeth and venemous spines.
When immersed in water while holding the fish in this manner, it will often spread it fins and allow a good photograph.

Underwater observations are, of course, desirable.

Happy hunting!

more at iSpot.org.za/Ideal_Fish

Groups:

June 2013

Surely a record month?
26 Fish observations! All of them with good photographs.

Yay!

No!

26 great observations, but
Jan 2013: 27
Dec 2012: 34

So third highest so far - fantastic on its own, and at this rate 30 is predicted by month's end! (see http://ispot.org.za/stats%20update)

Would be nice to finally say that we are getting one fish per day (and then soon two or 3 or 10!).

Dec 2014?

The predictive powers of iSpot is astonishing.

Dec 2012!

Sorry: fixed from 2014 to 2012.

Hopefully December 2014 will be in the hundreds not the thirties.
In this case, let us hope that the predictive powers of iSpot will be out by at least an order of magnitude!
350 fish observations per month would be seriously cool! Could you cope?

Cope?

Fish are easy if the pics are good (like they have been lately).

With only 280-odd species of freshwater fish in southern Africa and Skeleton's (2001) book being a "complete guide", dealing with them is a breeze compared to, say, 18 000 beetle species (PGW 2004, p.186). What? 18thousand! is that correct??.

With another 400 species accounts in the "Coastal Fishes of SA" In Heemstra & Heemstra 2004, we're dealing with the equivalent of a single, smallish family of beetles, but with the taxonomy being far more settled.

Very few subspecies, thank goodness.

More obs will attract more knowledgeables and experts.

Vorentoe

I agree! We somehow just need to get started: various initiatives on the line.

But we need the cellphone app and that will have to wait for the big software revamp: I am furious - we were promised it years ago.

Would love to have a Bayesian Key to the fish: looks trivial from counting spines. If some could capture it we can do it!

And as you say: as it gets used it gets popular!

Fish keys

Spine counts overlap too much, and the spines and soft rays are difficult to discern in most pics.

I'm still working on the freshwater inverts. As soon as I get some relief from my current project, I'll put my head down and charge with the freshwater inverts key.

The Vachellias and Senegalias lend themselves to a cool Bayesian key. Anyone?

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