Saturday, February 12, 2011

Sawtooth Pin (Atrina serrata)

After a week of miserable winds and cold temperatures , I was finally able to enjoy a warmer and sunnier day out on the mud and sea grass flats the winter tides had left behind here in Port O'Connor.
Even as I was out on the mucky surface the tides were rushing out.

Sea life left behind was sparse but the birds were plentiful, including a Red Knot, an unlikely visitor to mudflats. As seen below the Reddish Egrets are coming into their own and were fishing the shallows for very tiny fry. Evidence of Raccoon people was everywhere as they fed on the dead fish washed ashore by the recent arctic blasts. They prefer "Speckled Trout" but I followed tracks to several hardhead catfish where the animals tended to eat only the belly and entrails.

My best find was this Sawtooth Pin (Atrina Serrata) not that they are very rare but this is perhaps the largest individual I have ever found, coming in at just shy of 10 inches. These mollusks are listed as being occasional by McAlister (1993) in the Matagorda Island area but are however washed in by the hundreds on the surf beaches when there are major storms where they are light enough to reach the upper tide perimeters.  The interior of the shells is a blaze of iridescent if the rather fragile shells are found before abrasive sands have taken their tolls.  Below that brown exterior is a rainbow of color.

What is rather strange about these and related bivalves, is that they use their adductor muscles to actually bend the shell closed whereas most bivalves use the muscles at the hinge of the shells to close up.

I have always found these animals to be very difficult to find as live specimens in the bays. For me this one is a brute. Made my day.

Here are also a couple of Reddish Egret photos.
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