Guidelines for photographing, fixing and preserving corals and sponges

(To be used with the Identification Guide for corals and sponges for use by sea-going observers the SEAFO Convention Area)  

GENERAL CONSIDERATIONS

Step 1. For each trip observers are requested to photograph specimens of a representative collection of the corals and sponges observed in catches.

Step 2. Where possible, a specimens collection should be frozen or preserved using the methods described below. Only specimens in good condition should be preserved. However, if all specimens taken in catches are usually damaged then a representative sample should be preserved.

PRESERVATION METHODOLOGY

a) For corals – these should be preserved with 80% alcohol.

80% alcohol: method of preparation.

Dilute 8 parts of 100% ethanol in 2 parts of fresh water.

b) For sponges – these should be preserved with 4% formaldehyde

4% formaldehyde: method of preparation.

Commercial available formalin is a 37% solution of formaldehyde.

For a 4% formaldehyde solution, dilute one part of the 37% (commercial) formaldehyde in 9 parts of sea water. A buffering agent (Borax: sodium tetraborate) should be added to prevent the dissolution of calcareous material (one spoonful/litre).

Formaldehyde should be handled with extreme caution (toxic, carcinogenic substance!)

Preparation of fixatives should be carried out ashore before commencing the trip.

For preservation using formaldehyde or alcohol, keep the specimens in plastic containers of adequate size and add the preservative solution until the specimens are completely submerged.

All samples must be clearly labelled: A label including: vessel; gear, best estimate of spatial position of capture (decimal latitude and longitude to the nearest minute) date, depth and taxon name must be placed inside each container. The labels, made in resistant paper, should be written in pencil. Each container should be also externally labelled with the same information (using a permanent marker)

TABLE: FIXATION AND PRESERVATION OF DIFFERENT INVERTEBRATES

Other preservation methods

When it is not possible to use the above methods, samples should, where possible, be stored frozen. In this case, each sample must be placed in a plastic bag and clearly labelled internally (resistant paper label) and externally (permanent marker) with the information described above.

Specimens of some groups: Stylasteridae, Gorgonacea (including Primnoidae, Isididae and Chrysogorgiidae), Scleractinia and some Bryozoa, can be preserved by drying. For storage, the dried specimens must be placed in a plastic bag and clearly labelled (permanent marker) with the information described above.