Observation 212528: Collemopsidium foveolatum (A.L. Sm.) F. Mohr
When: 2015-08-10
Who: zaca
No herbarium specimen

Notes: This observation refers to the lichen growing on barnacles that is noticed as black dots over the shell.
Following the key in the reference one arrives to the pair of species C. foveolatum and C. sublitorale. They mainly differ by the size of perithecia, though overlaping (0.1-0.2 mm for the former and 0.15 – 0.5 mm for the latter). I estimate that the size of perithecia (involucrellum included) is consistently less than 0.2 mm, which makes C. foveolatum a good choice. I will try to make the microscopy, though the dimensions for the spores of the two species are also similar.


Microscopy: Legend – A) Lip shaped involucrellum (side view); B) Full perithecia; C) Top view of a perithecium; D) Pycnidium (similar to perithecia); E) Conidia cloud emerging from pycnidium; F) Asci and spores; G-I) Spores.
Barnacle eggs (?).

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Microscopy added.
By: zaca
2015-08-12 17:05:59 EDT (-0400)

I think that all the data from microscopy points to C. foveolatum, in particular:
the size of perithecia (always below 200 um); the lid shaped involucrellum in side view; the spores dimensions (though only a few were measured) with the following values:
(14.2) 14.3 – 21.2 (21.7) x (5.6) 5.9 – 7.9 (8.2) um
Q = (2.3) 2.32 – 2.86 (2.9) ; N = 12; Me = 17.3 × 6.8 um ; Qe = 2.5.
In the slide used I also found something of interest: though I’m not an expert in barnacle anatomy, I think that the last picture attached contains some photos of barnacle eggs.

Created: 2015-08-11 20:49:29 EDT (-0400)
Last modified: 2015-09-01 09:11:50 EDT (-0400)
Viewed: 34 times, last viewed: 2016-10-24 07:33:18 EDT (-0400)
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