raratt
Well-Known Member
BOO!
What did you accomplish today?
- Thread starter 420God
- Start date
BOO!
cannabineer
Ursus marijanus
cannabineer
Ursus marijanus
Why are you booing the post?
I think it's his ambition to become a pillar of the community[/QUOTE]
What could go wrong
He is soon to personally learn the definition of "exceeding column load".
ANC
Well-Known Member
Yeha man, I wanted to become a marine biologist at that stage. you should see my shell collection.
cannabineer
Ursus marijanus
Yah, as in spinal. That deck is about to go to eleven.
raratt
Well-Known Member
Bad joke.
cannabineer
Ursus marijanus
Good to know.
raratt
Well-Known Member
I thought it wasn't punny.
Roger A. Shrubber
Well-Known Member
i was just going by physical appearance, the conch has a ring at the edge of the eye that looks very much like a camera shutter. might just be the way it looks.
cannabineer
Ursus marijanus
Quite possibly! I did a perfunctory search for Strombus ocular anatomy, but ~sigh~ internet.
~edit~ I did find this.
Amer. Malac. Bull. 26: 3-18 (2008 )
https://www.researchgate.net/public..._Ecology_and_Evolution_of_the_Eye_in_Mollusca
Excerpt. No mention of an iris, so I'm not sure.
"Gastropoda
Except for a few genera, most gastropods have a pair of
cephalic eyes. Eye placement varies among gastropod
groups, and the eye can be located at the base of cephalic
tentacles, on the tips of retractable tentacles that can with-
draw the eye, or on short stalks. Gastropod eyes range from
open pits (Fig. 3A) to closed vesicles with or without lenses.
The majority of gastropod eyes are of the closed lenticular
type (Fig. 3B), composed of cornea, lens, vitreous body, and
a cup-shaped retina (but see heteropods below). The retina
can have multiple photoreceptor types (Table 1); however,
the majority of photoreceptors near the lens are microvillous
R cells that form rhabdomeres. Other photoreceptor cells
(e.g., H cells, basal retinal neurons -BRN) are ciliary (Chase
2002). Across species, there is considerable variation in reti-
nal composition (number of cells, photoreceptor density,
organization of photoreceptors) (Hamilton 1991, Chase
2002), but the functional significance of these differences
largely is unknown and unexplored. Generally, gastropod
eyes appear to have several functions including: mediating
phototaxic behavior and locomotion, regulating daily and
seasonal activities, and, in some species, visual detection of
forms. However, the extent to which gastropod eyes have
spatial vision is still under investigation (Zieger and Meyer-
Rochow 200
and will probably vary greatly among species.There are several unique structures in the gastropod
sensory system. The “accessory retina”(Smith 1906) is
found in some gastropod lineages (e.g., Limacidae), which
may be involved in infrared detection (Newell and Newell
196
. Dorsal eyes appear in species of the marine slug On-chidium Buchanan, 1800. These eyes are on papillae pro-
jecting off the dorsum of the animal (Hirasaka 1922) and are
composed of ciliary photoreceptors that may create a “rea-
sonable image”(Land 196
. See detailed descriptions inKatagiri et al. (2002) and references therein. Probably the
most sophisticated and unique eye in the gastropods is the
scanning lenticular eye of pelagic heteropods. The retina is
not cup-shaped but forms a long strip of 3-6 cells in width,
resulting in a very narrow field of view and contains several
photoreceptor types that are unlike ciliary or rhabdomeric
receptors found in cephalic eyes of other molluscs (Land
1984). These eyes move in a systematic scanning motion,
which may be used to detect stationary objects (Land 1982).
Further work on the function of these unusual eyes is
needed. For more information on gastropod eye diversity,
there are several excellent and comprehensive reviews
(Charles 1966, Messenger 1981, Chase 2002, Zieger and
Meyer-Rochow 200
."
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ANC
Well-Known Member
Roger A. Shrubber
Well-Known Member
I'd like to - have never been to Africa but I bet you have some kick ass shells there.
Speaking of shells I found this calcified Queen Conch in a Calusa shell mound on the SW side of Florida back in the 60's (on the coast near the Everglades) - you can clearly see where someone bashed the shell (pic #3 in the upper whorl) to break the animal's suction so it could be eaten.
Chunky Stool
Well-Known Member
cannabineer
Ursus marijanus
too larry
Well-Known Member
A couple of three weeks ago my customers had a low county boil. Very good.Oh yeah! My daughter could almost eat her weight in them.
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