More on Mollusks

      Mollusk collection has finally begun in full force.  Beyond general surveying to examine mollusk range as an indicator species for greater issues such as sea level rise, biodiversity loss in increased temperatures, sensitivity to pH levels etc... we will be extracting DNA samples for genetic analysis for the Barcode of Life Initiative.  Obtaining this genetic data will define species boundaries which can be difficult due to solely based on morphology due to phenotypical variation. Thus a baseline catalogue of of species will become accessible which is essential to identify what exactly it is we are trying to conserve.  All data is gathered into the worldwide BOLD database which offers morphological and geographical data on the species in addition to the barcodes.  As the database grows I think it will be interesting to examine the ecophenotypes and genetic variability by region offering insight into their evolution and species delimitation.  As a strong database continues to develop it will have many additional uses such as determining the diets and trophic levels of organisms by doing gut samples and obtaining DNA from the prey in the stomach and intestines and thus identifying exactly what it has eaten by matching barcodes from gut contents to barcodes in the database.  This would me much more accurate and easier than current gut analysis techniques as the food that is too digested to be identified normally could still be identified by obtaining DNA that would still be extractable.  Another increasingly common application of DNA barcode information is using it to crackdown on seafood fraud which has become more prevalent in recent years.  Currently the FDA is utilising this information and it is likely that other agencies will begin to as well given the success the FDA is having.  As the database becomes more complete (it encompasses all species not just mollusks, mollusks are just the category that is most in need of genetic analysis currently) it will become more widely utilised for a range of research and practical applications.

     Within the next month we are hoping to collect 200 species of mollusks with 2 specimens of each species.  Last Wednesday's collection yielded approximately our first 30 species from rocky shore habitats at Mulloway Beach and Thursday was a day of diving to survey South and Split Solitary Island's mollusks and collect on the third dive at Muttonbird Island.  Unfortunately currents were strong and visibility dropped from about 12 meters at Split and South to 1 meter at Muttonbird so we were only able to collect about 10 species.  This week we did a rocky shore collection from Woolgoolga and I was fortunate to have the help of a few of Steve's (the head mollusk researcher at the NMSC) third year marine science students to turn some boulders and search for mollusks.  We found another 20 or so species we had not yet collected but I was worried we might lose a couple when the guys thought it would be funny to put an octopus in my bucket of samples, needless to say octopus love eating mollusks.  It all worked out in the end despite an angry octopus spraying me with water and causing a scene while trying to get it out of the bucket before it ate any samples.  After the slight ordeal, I still have plenty of mollusks from the last 2 weeks to keep me busy for awhile. Collecting will prove to be the easy part;  After getting some photos for each specimen they go into 95% ethanol until I will have time to dissect them in the lab.  I have to obtain a tissue sample without contaminating it with any contents from the stomach or intestines in order to get a clean DNA sample.  For bivalves it is supposed to be ideal to sample from the adductor muscle and for gastropods just behind the operculum but the smaller the mollusk the harder it becomes.  I have a feeling by it is going to take all 400 samples to master the best technique! 

I will try and get some mollusk photos up soon!