Not a Carinaria – expert review – Petroacheid – possible world record!

Pterotrachea coronata

Pterotrachea coronata

This is our original post: Whilst at Shelly Beach Bermagui last Sunday(August 26 2012), Michael found the largest Carinaria yet. It was around 35cm long from feeding tube to tailtip. Although it had lost its shell, we could clearly see its feeding “trunk”, what looked like elementary “eyes” and its gut. It had fins underneath its body and a tail with tiny rows of markings. Here are the photographs Michael took later. We are still trying to find out more about these strange creatures. Please do keep a look out and report any sightings. Yesterday we received the post below from an expert, Roger Seapy. We had been finding Carinaria, as we have photos of their shells, but this obviously was another species altogether. Wow!

Carinaria found 26/8/12

Carinaria found 26/8/12

1 reply
  1. Roger Seapy
    Roger Seapy says:

    the specimen found by Michael McMaster is not a carinariid; rather it is a pterotracheid, Pterotrachea coronata. the carinariids possess a shell that covers – and protects – the stalked visceral mass (guts, gonads, gills, etc.); while the pterotracheids lack a shell and the visceral mass is compressed into an elongate, tear-drop shaped “nucleus” that gains some protection by being imbedded in the transparent, gelatinous body (see second photo). the eyes are well-formed, with a lens that focuses visual images onto a retina (see eye structure on the website given above). interestingly, this is the only group of gastropod mollusks with image-forming eyes. Considerably more information on this species is given on the above website.

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