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WAM-TS Preservation and Lodgement of Marine Specimens

Preservation and Lodgement of Marine Fauna

Version 2 (Oct 2011)

PRESERVATION

As a general rule,anethanol solution >75% can be used to preserve specimens, however many animal groups require specific preservation methods to preserve diagnostic characters. Likewise larger animals generally may be frozen, as long as they remain frozen from the time of collection until their arrival at the Museum. Decomposing specimens will be rejected, except in cases where they had to be taken from the hull of a vessel on the slips. Specimens should be placed in preservative as soon as possible after collection/removal from the water.

Ethanol preservation

The dilution of ethanol should be made using distilled water, and not sea water.

Formalin preservation

A 4% formaldehyde (= 10 % formalin) solution should be made up using sea water not freshwater. As Formalin is acidic (pH 3–4.6) it can quickly dissolve calcareous structures. Sea water acts as a partial buffer, but only temporarily.

Freezing

Soft-bodied, gelatinous animals should be chilled prior to freezing. Rapid freezing can cause ice crystal to form too quickly damaging delicate tissues such as the internal organs. This is particularly important for animals that require anatomical or histological examination such as oysters, some mussels, flatworms and sea anemones. Fragile or delicate specimens should be frozen in seawater as an ice block to prevent mechanical damage during transport.

Narcotising

Many gelatinous taxa require narcotising prior to preservation. Narcotising the animal effectively relaxes the animal preventing the innate defensive mechanisms induced by the shock of placing the animal in preservative. Sea anemones (Cnidaria; Anthozoa) as an example typically retract their tentacles upon coming into contact with ethanol, the contracted muscles are surprisingly hard and make examination difficult. Bivalves such as oysters and mussels close their valves tightly, preventing the preservation of the soft parts necessary for species identification Typical narcotising methods include refrigerating specimens, bathing them in a solution of magnesium chloride (MgCL2) or menthol crystals.

Table 1. Preservation methods for key taxa

Taxa / Narcotise? / Preservation / Notes
Annelids
Leeches / Y / 75% ETOH / Refrigerate in seawater (if marine species) for 30 min prior to preservation in ethanol
Oligochaetes / 75% ETOH
Polychaetes / 75% ETOH
Ascidians / Y / 75 % ETOH or Freeze / put in container in feshwater and add MgCl and put in fridge to relax before preservation
Bryozoans / 75 % ETOH or Freeze
Cnidaria
hard corals / dry or 75%ETOH / to dry: bleach/rinse/dry keep a duplicate in ETOH
soft corals / 75 % ETOH or Freeze / small in ETOH - large freeze
sea pens / 75 % ETOH or Freeze / small in ETOH - large freeze
Crustaceans / 75 % ETOH or Freeze / small and delicate specimens preferably preserved in ethanol, if not then freeze in a small amount of seawater for protection.
Echinoderms
Holothurians / Y / Freeze or 75%ETOH / Refrigerate in seawater for 30 min prior to preservation in ethanol
Echinoids / Freeze or 75%ETOH
Asteroids / Freeze or 75% ETOH
Crinoids / Y / ETOH / Place in container with label between layers of paper towel, add 75% ETOH carefully, place layer of paper towel on top and press down unitl flat and animal relaxs. Lift towel and adjust animal, return paper towel and add next specimens. DON’T FREEZE
Ophiuroids / Y / Freeze or 75% ETOH / Relax in MgCl - add solution to animal in seawater until half mgCl and half sw. on relaxed freeze flat or between layers of paper towel in ETOH as for crinoids
Fish / Freeze or 10% Formalin / When freezing, freeze the animal flat.
Incision into gut cavity on right hand side for specimens over approx. 30mm in length to facilitate internal preservation. Preserve in container large enough to allow specimens to lie flat (long eel-shaped specimens may be curled in half).

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WAM-TS Preservation and Lodgement of Marine Specimens

Molluscs
Bivalves etc / Y / Freeze or 75% ETOH / Bivalves/chitons/ scaphopods/gastropods except opisthobranchs
Shell of bivalves may be gently broken or edge chipped or bored to allow entry of ethanol (immediate effect)
Gradual addition of Magnesium chloride solution or ethanolto sea water to kill (may take 12 hours).
Cephalopods / Freeze or 75% ETOH / relax & kill in freshwater (take care that it cannot escape!), straighten tentacles, then freeze
Opisthobranchs / Y / 100% ETOH / photograph live animal moving in sea water, needs tentacles out, may need to leave a while to recover, put animal in vial in sw in fridge, to kill, may need to leave overnight, or in freezer until water just starts to form ice on surface - not the whole lot. Touch rhinophore to see if still alive - when dead put in ETOH. photo should be numbered & identical number put with specimen
Sponges / 75 % ETOH or Freeze / small in ETOH - large freeze

Colour photographs

Colour photographs of live or freshly killed specimens are desirable as colours may fade or change after death and preservation. Please note photographs are generally not enough for identification to species level. For fish, photographs should be of the left side of the animal.

DNA preservation

Sample of each species very desirable. As a general guideline use 100% ethanol where appropriate. For fish, take tissue samples from right hand side.

Storage

Each container should contain a unique coded identifier that we can quote when supplying identifications.

Each container should contain a small printed label specifying the concentration of the ethanol (e.g. “100% ETOH” or “75% ETOH”).

Appropriate glassware is preferred as this is how the specimens will be permanently stored. Frozen specimens should be placed in plastic bags or jars.

Labels

Each sample lot should contain a clearly printed label with the following specifications:

  • Locality information should include: Country, state, island, landmark, (or river/stream etc if freshwater) site details, substrate, depth.
  • Use Latitudes and Longitudes (DD°MM’SS”) NOT UTMs or decimal degrees. Seconds can be up to two digits after the comma. Specify the datum (e.g. WGS84, GDA94)
  • Date collectedin following format; dd/mm/yyyy
  • Collector & organisation.
  • Collecting method, time of day.
  • Habitat: i.e. marine, brackish or freshwater

Do not rely on external labelling. Labels must be placed inside the container. Permanent marker can easily be rubbed off from plastic surfaces or dissolved in solvents such as ethanol.

Electronic data

Please provide electronic data with your specimens for direct import into the WAM database. Use the columns in your Excel spreadsheet as per the aproppriate database template with the maximum number of characters per column as indicated (our database fields have length restrictions and any data exceeding this length will be truncated and is lost, or data import doesn’t work).

Please format all fields in your Excel spreadsheet as “Text”, e.g. the date field should not be automatically formatted as date!!

Identification

At this point, the identifications of specimens belonging to the groups Annelida, Ascidiacea, Bryozoa and Cnidariaare available only by outsourcing. In such cases you would be contacted to determine if you wish to proceed.

Delivery

  • Specimens should be delivered to the WesternAustralianMuseum after filling out the on-line submission form on the WesternAustralianMuseum website:
  • When attaching electronic data for the specimens, please make sure they are formatted as requested in the WAM database template that is also available on the WA Museum submission website and described in Appendix 1 (fill out yellow columns only following appropriate field character number restrictions) for ease of transfer of data to our database.
  • You will be sent a project-specific chain of custody receipt once the submission has been checked.
  • Please print the chain of custody receipt in triplicate for signing upon delivery of the specimens

Checklist:

Storage and labelling:

Specimens in SAMCO vials or suitable jars

If extra tissue in 100% ethanol: 2 ml Cryotube used

All labels onTablex Board

All labelsfixedby cooking 20-30min at 100°C

Label with unique coded identifier

Label: “75%EtOH” or “100%EtOH”

Locality label in 4.5 font Arial

Locality label: locality with gazetteer reference

Locality label: coordinates in DD°MM’SS.SS”S, DD°MM’SS.SS”E (not UTM or decimal degrees) and with datum (WGS84 or GDA94)

Locality label: date with month spelled out (abbreviated) - not as a number, and full year(e.g. 16 Oct. 2008)

Label size: max. 35mm x 10mm.

Spare locality labels if more than one species is suspectedin the contents of a vial.

Delivery:

Before delivery fill out on-line submission form at:

Print chain of custody forms in triplicate and bring with specimens to the museum

Upon arrival at the museum – sign off on chain of custody documents