Clathromorphum “compactum(1)” (Ar/A)

To date we have only 16 genetically verified records from northern Labrador, NL, and the Bay of Fundy, NB. Individuals grow on hard substrata from upper intertidal pools to 12 m subtidal. This is one of the thicker coralline crusts in the NW Atlantic flora (Image A), which has obvious layers of buried conceptacles when a fractured surface is viewed (Image B).

In their study of Clathromorphum, Adey et al. (2015) actually have two distinct genetic groups assigned to this C. compactum. This genetic group is not bona fide C. compactum and requires a different (new) name. In our ~150 collections of Clathromorphum spp. we have yet to encounter bona fide C. compactum as assigned in Adey et al. Taxonomic work is needed.

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Image A. Habit of crust overgrowing Phymatolithon (GWS008858) displaying the typical mound-like appearance of this species (Beaver Harbour, NB; GWS008857).

DSCN5636.JPGImage B. Low magnification view of fractured crust revealing layering of perithallus and rows of buried conceptacles (GWS008857). Scale = mm ruler.