COLLECTION & PRESERVATION

OF SPONGES &

ECHINODERMSMuneer A

Reg.no. 140509Dept. of Aquatic

Biology& FisheriesMob.8129458711

Introduction Collection and preservation - essential

for the taxonomic study of invertebrates

Require techniques for collection and preservation – because poorly preserved material produce complicated results.

Carefully record- available biotic or abiotic @ the collection site.

Phylum Porifera – generally SPONGES- Unique group of animals & most ancestral metazoan

World Porifera data base enlist 8132 species

Ecologically & economically – important group

Unique collar-cells Echinoderms – consist of over 6500

species in six classes Echinoderms- only animal with mutable

connective tissue

Collection and preservation of sponges

Sponges are multicellular organism without true tissue

Exclusively aquatic- most in marine Distribution- from the intertidal to

hadal depths

Collection of sponges

Sponges- mainly found on hard rock, substrates also occurs on algae and loose stable bottom sediments

Diversity- variable & unpredictable Actual collection not simple Sponges are soft bodied, many are fragile

and colours are generally unstable Massive or erect sponges are normally

easy to spot

Encrusting sponges- more cryptic owing to their small size and location

Sponges removed from the substrate using knife or chisel

Protecting cloths are preferred

Clathrina clara: specimen on Pinctada

fucata shell

Many sponges are harmful to human . By, Producing physical damage Producing Irritating mucus and some

chemicals cause severe dermatitis Eg: Neofibularia sp.

So take special care must be taken minimizing damages to both collector and specimen

Collection maybe different kinds: Some times collect fully processed

specimen only A few specimen per shore trip Collect representative part only

To avoid spicule contamination , separate containers are used

Numbered polythene bags are ideal for diving

Preservation of sponges Sponges should be frozen immediately

upon collection They will keep fresh for few hours The live material placed directly in 80-

90% ethanol solution 5% buffered formaldehyde is a less

preferable alternative only for brief period

Calcareous sponges should not be fixed or preserved in formaldehyde

Traditionally , sponges preserved dry in sun light- may lose their colour and shape

It is not good for subsequent preparation and microscopic examination

Samples for DNA extraction should be cut into small pieces & alcohol must changed few hours and dehydrate the specimen completely

Strong fibre skeletons groups: may be rotted in freshwater subsequently washed in solutions of

potassium per manganate and then sodium meta bi sulphide

for softens and cleans the fibrous skeleton from incorporated sand particles

Collection and preservation of echinoderms The Echinodermata consist of over 6500

living species Distribution: intertidal zone to the

deepest ocean trenches Ecological significance Echinoderms are the only animal with

mutable connective tissue

Feather star on the Great Barrier Reef in

Australia

Collection of echinoderms Most echinoderm have manipulated

with naked hand Smallest individuals with forceps SCUBA is used for the collection Most echinoderms are cryptic&

nocturnal Some live on the surface of substrate or

in host organism

Borrowing brittle stars , sea cucumbers, and sea urchins are associated with root of sea grasses and soft sediments

Echinoderms are found in under water rocks and slabs of coral rubble

Also be extracted from chunks of rocks and algal substrates , These are held in containers of

sea water until the medium is hypoxic, or adding a low concentration of formalin or alcohol to irritate and drive animals out of the crevices

Preservation of echinoderms Basic preservation procedure- the

specimens placed in a tightly sealed container of 70% alcohol

Formalin used as a preservative for most echinoderms

But, sea cucumbers always stored in alcohol because formalin dissolve the calcareous ossicle

Dry preservation is also in some

Warty sea cucumber, Parasttichopus parvimensis

Warty Sea cucumber, Parastichopus parvimensis

Steps for MUSEUM QUALITY specimen preparation:► Cleaning: Animals that are covered

with sediment or debris should be gently agitated or rinsed with a stream of sea water

► Relaxation: relaxation prevents specimens from breaking or controlling when they are preserved.

Echinoderms are anesthetised in covered trays, which exclude light , by soaking them in isotonic magnesium chloride or magnesium sulphate solutions

► Relaxation with magnesium chloride is a preferred treatment for specimens to be used for histological analysis

► Preservation: Best preservative is 70% ethanol , but some times formalin can be substituted

The tentacles of completely relaxed sea cucumbers will not contract when individuals are transferred to alcohol

Very large animals with a thick body wall, should be preserved using Alcohol injection

In sea cucumber- 95% alcohol injected carefully though anus with a hypodermic syringe

Sea urchins can be transferred from sea water to alcohol without any relaxation treatment

most echinoderms- preserved in 5-10% formalin

Sea urchin

Initial preservation in formalin maybe beneficial for large specimens of sea stars and sea urchins.

They should be transferred to alcohol to remove formalin and salt, specimen

should be soaked over night in distilled water before the transfer

Alcohol preservation- most satisfactory method for long term storage

It inhibit the deterioration of skeleton & soft tissue

skeleton & soft tissue- treated differently

There are key to identification

For DNA sequencing– consist: Arm or arm portion of Asteroids Portion of body wall of

holothurians

Sea cucumber(class Holothuroidea)

Sea star(Class Asteroidea)

Conclusion Collection and preservation of aquatic

organisms are necessary for taxonomic studies

To avoid damage, perfect techniques are required

Collection of sponges and echinoderms- generally using SCUBA

Simple equipment- forceps, knife/ chisel- used for the collection

Collector should take care to avoid irritation produced by some sponges

In the case of sponges- Ethanol is most preferred preservative than formaldehyde

In echinoderms- formalin normally using , not in sea cucumber

In the case of large echinoderms – preserved in formalin and transferred to alcohol

Reference Hendler, G , (2004)“Collecting,

preserving and archiving Echinoderms” Natural history museum , Los Angles (http://clade.ansp.org)

Ackers , R.G., Moss ,D. & Picton, B (1992) “Sponges of the British isles (Sponge guide V), A Colour guide and working document” Marine conservation society, Ross-on-Wye, England 165pp.

Hooper, J.N.A (2003) “Sponge Guide: guide to sponge collection and identification”, Queensland museum, Brisbane , Australia. 26pp

Photo courtesy:

www.mhhse.com (chapter 7, Echinoderms)

Veena, S & Lekshmilatha, P: “Clathrina clara (calcarea: clathrinida:Clathrinidae) as foulers on onshore farmed oysters (Pinctada fucata)”, regional centre of CMFRI, Vishakhapatnam, India

THANK YOU. .

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