Bonaire, September 2012 ~ This is why they are called spinyheads! I have been examining Ned’s photo of a Spinyhead Blenny (Acanthemblemaria spinosa) for the past 30 minutes – I cannot get over the detail. Even with a flat port, diopter and tripod, I have never been able to capture a close-up video portrait that would allow me to examine the cirri and spines on the fuzzy little heads of these 1-inch fish.
The amount and location of the cranial spines (the ones on top of their heads) and the form of the orbital cirri (the ones over their eyes) are important in visual identification. We blennywatchers use them to differentiate species in the genus Acanthemblemaria. Called tube blennies because they occupy abandoned worm tubes in both live and dead coral, they perch with just their heads showing. They are often found in shallow, surgy water and the fish geek in me wants to look at them in all their speckled, branched and spinescent glory on the steady screen of my laptop.
Here in Bonaire, where we are spending the month, Spinyheads are the most commonly sighted tube blennies. They have spindly cirri above their eyes with a few branches and their eyes are usually yellow or green. I love this photo – you can even see the vomerine teeth – the patch of teeth located in the roof of the mouth. Click on this image below to see what I am talking about:
Medusa Blennies, Acanthemblemaria medusa, are a little more difficult to find. They prefer really shallow areas but where we find one, we usually find a colony. I have found 6 to 10 on the same rock for at least the past five years – so close to shore that I can direct people to them from the dock. The speckled iris is one of the visual identification clues for the Medusa Blenny. Their cirri are deeply branched and the papillae on their head spines are fleshy and dense. They are unmistakably different from the Spinyhead Blenny:
Many thanks to our friend, Dr. Bill Smith-Vaniz, for patiently answering my many blenny questions. One of his especially informative blenny papers is available online (on one of the journals that charges a small fee): Atlantic Fishes of the Genus Acanthemblemaria, with Description of Three New Species and Comments on Pacific Species (Clinidae: Chaenopsinae) by William Smith-Vaniz and Francisco Palacio.