Basics of Fish Identification

13 Apr 2015


As instructors we often get the question "I saw a yellow fish – what was it?"


Answer "I dunno, haven’t a foggiest!"


Colour is just one part of fish identification and please remember what happens to colour as we get deeper – think of your open water theory.  As we go deeper more and more colour is lost. By 10m red has virtually disappeared.


So colour has a place but its use must be tempered with common sense, besides there are many yellow fish. Ok what else can we use?


Size – is important!  Is it big, little or tiny! 

  1. Shape – body / head / lips

  2. Patterns – patterns are great, they are reliable and can be used to separate closely related species.

  3. Fins – shape another reliable feature.

  4. Specialized features – some fish have prominent specializations especially to their fins – this makes them very distinctive 

  5. Swimming action – a useful guide

  6. Location – where you saw it – you may realize that what you though was one species may in fact be another because it was in the wrong place or you have an invader!!! Click on lionfish.

  7. Behaviour – shy, curious, aggressive – Clownfish very territorial!!

  8. Feeding habits 


So for proper fish identification you will need to:

  1. Observe - Observation is a passive interaction with the fish do not chase and terrorise it.

  2. Record – have a method of recording what you see slate / camera / incredible memory.

  3. Analyse – look at your data and recognise the main identifying feature/s of the fish

  4. Identify – use a reference book to identify your fish, use identification keys quickly and easily

  5. Practice, practice, practice – ask for help 

What to do? Enrol on the AWARE Fish ID Speciality: contact Splash today.


Prerequisites: PADI (Junior) Open Water or equivalent

Minimum age: 10 years


What will you do?


Study PADI Fish ID Specialty notes in Adventures in Diving Manual: Complete Knowledge Review and two open water dives.



Coming up a look at the all New Project AWARE Distinctive Speciality Dive against Debris Join us for a 2015 Splash for Trash day!


Join project Aware and check out the incredible resources. Down load Our World, Our Water a fantastic FREE guide to the underwater world.


Look at Dive against Debris and many more!!


Happy Fish watchin’


Big Rob:



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