Bulletin 20 - July 1983: New Procedure for Marine Fish Observations/Recordings



New Procedure for Marine Fish Observations/Recordings

by R.W. Brown

The purpose of this article is to introduce a new observer recording technique to the ENHG. A new recording form has been drawn up which will be discussed along with a typical example of its use. It is not intended, at this stage, to go into the precise detail of marine fish identification. However, those interested in the basis of such identification may refer to the article in Bulletin No.4, pp. 24 -26.

The Observer Recording Form

A completed example is attached to this article. As can be seen, the form is divided into two parts, the first to be completed by the observer and the second by the marine recorder later.

The first section is subdivided into seven parts (A -G) which, if completed accurately, should enable a positive identification to be made. In order to assist observers, two visual aid reference sheets have been prepared, viz:

- Diagramatic Sheet 1: Body Shapes
- Diagramatic Sheet 2: Head and Tail Shapes

These sheets, in conjunction with the observer form, provide a simple 'identikit' reference for use on site. It should be noted that if a particular fish spotted corresponds exactly with that on Diagramatic Sheet 1, then the head and tail references can be omitted. The reference sheets are designed for simplicity, but such sheets are rarely complete, there usually being another species to be discovered. If a body shape does not appear to be covered, there is a space on the form for a sketch. The same applies for heads and tails.

Examples

The following completed form is based on the information for the fish Thalassoma lunae (see preceding article). The marine recorder will have received the observer's form and attempted a positive identification. This, of course, is made all the easier if accurate and concise data are provided. After identification the record is entered or a new record card made out, as appropriate.

Further Study

Practice in the use of the reference sheets and completion of observer forms could be obtained by attempting to write down the pertinent details from marine fish articles in previous Bulletins. A list of articles is attached.

Once the principles of fish recording are generally understood, prospective observers should get out and observe, remembering to take out blank forms and reference data (perhaps in plastic covers). Completed forms should be returned to the marine recorder or any ENHG Committee member.

Handling Fish

There are only two methods of observing fish specimens - in the wet or in the dry. Safe handling procedures for fish out of water are very important. Dorsal and anal fins contain sharp spines which in some species are poisonous. Furthermore, some fish can survive for several hours out of water and still bite. A good pair of gloves come in handy when examining any specimen, whether dead or alive.

Divers observing in the water should also take care. Most fish will swim away from fear, but some, especially the stone fishes, do not. These fish, Family Synanceiidae, are rarely found in Abu Dhabi inshore areas but are common along the east coast. They will sit quite happily on a stone or rock and strike when approached. A sting from the dorsal spine of a stone fish is at best very painful and can be fatal. However, the rewards of underwater observing are well worthwhile. Photography provides one of the best general methods of fish recording, but fin counts are virtually impossible. It is hoped that these notes will spur on would-be observers to become active in completing the forms.


    

    

 


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