Collection, Preservation and Labelling of Molluscs

BY: Salvo Sarcia Sinogba Ternida Testa

Collection of Molluscs

2 Types of Collection Dead Collecting

Collection of dead mollusc Live Collecting

Collection of live mollusc

Instruments for Collection Allison Scoop

Used to collect molluscs from stream bottoms, specifically Campeloma (a freshwater gastropod).

The scoop is triangular in shape (which serves as the basket in order to catch molluscs)

Ferris Hoe A tool for pulling or turning over of the

logs and woods, and digging through rotten leaves around the stumps.

Davis rake drag It is used by throwing the device to the

water (sea/ freshwater) in order to gather substrates. The device is pulled by the rope attached to it. It is tilted and emptied afterwards in order to collect the desired specimens.

Screens, deepers, nets Used to collect specimens from shallow

water.

Van Eeden Scoop The scoop is designed for collecting

freshwater molluscs.

Shovels Used to dig up clams. Also called as clam gun.

Clam tube Used for drilling sediments Used for collecting clams

Hammer Can be used for scraping Can be used for digging Can be used for turning over rocks

Bales Hook A rod with one looped end. Used for pulling and turning over

Water Pump Used to collect fine-sized molluscs.

Bags and Collecting Containers Serves as the storage room of collected

mollusc specimens

Light Forceps/ Tweezers Loupes Threads

In collecting molluscs The habitat shall be considered.

For example terrestrial, freshwater or marine.

Shallow or deep phase of the marine or freshwater ecosystem.

A specific tool may only be used to a specific mollusc species.

You cannot use water pump when collecting large-sized molluscs.

A rake is not advisable when collecting fine-sized molluscs.

Source: http://books.google.com.ph/books?id

=-NbmHx93s8gC&pg=PA10&lpg=PA10&dq=collecting+mollusk&source=bl&ots=DrAsVuhXTH&sig=KrcFFt-_SHC0TypCRctT2VSQ2vs&hl=en&sa=X&ei=4LgCUNSCLNCOmQWHiIzrCQ&ved=0CF0Q6AEwCQ#v=onepage&q=collecting%20mollusk&f=true

Preservation of Molluscs

Three Stages of Mollusc Preservation

Narcotization/ Anaesthization Killing and Fixation Permanent Preservation

Narcotization/ Anaesthization Menthol Magnesium chloride: The

animals are kept in clean water in an enamel tray / Petri dish / bowl depending on the size of the sample. Powdered menthol or magnesium chloride is sprinkled over the water and covered with a lid. The sample is left undisturbed for at least 12 hours.

Narcotization/ Anaesthization Alcohol or Chloral hydrate: 70% Ethyl

alcohol or 1 % Chloral hydrate is added drop by drop at frequent intervals to water in which animals are kept and ensuring that the sample is covered with a lid.

Killing/ Fixation The common chemical used for

fixation of animals in the field is 4 to 10% neutral formalin solution.

After fixing and soaking the specimen in water, transfer it to 75% alcohol.

Permanent Preservation Methods of Preservation

Boiling 90% AlcoholFreezingMicrowavingUsing insects or sea anemonesFormaldehyde

Boiling Cleaned by boiling and removing the

animal. Bodies of gastropods are easily

removed when hot.

Microwaving Wrap each shell with towel. Put the wrapped shell in a dish and

microwave. Carefully remove the bodies by

screwing it out.

LabellingSpecimens preserved in ethanol vials should

be labelled with locality and taxonomic name labels, placed inside the vial with the specimen. Those labels must be printed with ethanol-proof ink. The labels placed inside of specimen vials may be of various sizes, depending upon the size of the vial. The label must fit within the vial. We recommend using pinned specimen label size and format. Basically, use the same types of labels for both pinned specimens, and specimens preserved in ethanol. The only significant difference is that the ink must be ethanol-proof, and the label paper must be alcohol/chemical resistant (e.g.: Forbon, Resistal, 100% rag content, Tyvek).

Labelling Specimens are labelled the same

way as the other organisms. Same rules are applied.