#mollusc

Most of my marine bio art can be bought as prints from my store here!

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Thank you!! You as well!

over the last year, more and more people on reddit have brought to my attention a new man made horror beyond my comprehension: the expansion of "acid dipping" to the neritid family of aquatic snails.

https://www.reddit.com/r/AquaticSnails/s/vPCUTXWyAq

this heinous practice has been applied to other pet snails for a longer while, but the reports of treated nerite snails are new, and steadily increasing.

as the name implies, these snails are submerged in an acidic solution and/or sanded down with tools to give them the "rare" or "novelty" white shell colour and then sold for higher prices.

not only is the process stressful and potentially lethal for the snail, the white colour is achieved by stripping the shell of its outermost layer called the periostracum.

https://aquariumbreeder.com/snails-external-anatomy/

the periostracum acts as a protection for the prismatic layer below it, which is more susceptible to erosion, giving the snail a lifelong impediment. THESE SNAILS CANNOT REPAIR OLD SHELL GROWTH. THE NEW SHELL GROWTH HOWEVER WILL APPEAR IN ITS NATURAL FORM AND COLOUR.

in this context it is important to note that all, or at least 99.99%, of nerite snails that are sold are wild caught animals as successful captive breeding is currently not possible at a meaningful scale. surviving transport and adjusting to captivity is already a major stressor to them without the nonsense of human aesthetic preferences.

so far i have seen one species in particular targeted by bleaching, Neritina pulligera (aka: military helmet nerite, steel helmet snail, dusky nerite, black/brown/olive racer nerite, algae snail or algae nerite). this species is naturally a shade between jet black, dark brown and olive green or light brown. in the pictures you can see areas of these colours where the shell was not stripped very thoroughly. they are sold under the name "beluga nerite" or "beluga snail", or as "white [common name]".

in the aquarium trade, naturally plain white nerite snails are extremely rare, if not unavailable - some species can have a whiteish/cream/light grey base colour with a distinct pattern in black, brown, pink, green, etc. on top of it. if in doubt, assume it is acid dipped, and do not support this trend.

https://www.reddit.com/r/AquaticSnails/s/jNDmUge7uj

Shikamaia akasakaensis was a giant bivalve that lived during the mid-Permian (~274-267 million years ago), in the shallow tropical waters of a carbonate platform atop an oceanic seamount in the region of what is now Japan.

It had a long flat shell up to about 1m (3'3") long, with a raised triangular hump at the front and wing-like flanges at the sides — a shape that helped to spread out its weight on the soft seafloor sediment.

Its shell was once thought to have been translucent, allowing it to host symbiotic photosynthetic algae inside its body tissues and providing it with the extra sustenance needed to grow to such a huge size. However, more recent studies suggest its shell was actually opaque to sunlight, so instead it may have hosted chemosynthetic bacteria similar to some modern clams.

…Or, considering that it shared its habitat with some other big invertebrates such as a large species of the marine snail Euconospira and a giant crinoid, Shikamaia could simply have been living in such an incredibly food-rich environment that it was able to attain gigantic sizes purely from normal filter-feeding.

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how do we feel about very small snails?

many land snails are very small, even some smaller than these, but they’re easy to miss even if you’re already accustomed to looking for tiny invertebrates.