Trouchus snail lifespan?

[joec]

I put 5 adults in new display in February, supplemented at first algae although less lately. Slowly they've died off with the 4th one now showing signs of going down hill similar to the others. They all seem to start with not or barely moving for a few days, but still alive, to not moving at all and seemingly dead a few days later.

Parameters seem fine, nitrates around 10 or less.

Is this normal?

 

[Sashaka]

I put 5 adults in new display in February, supplemented at first algae although less lately. Slowly they've died off with the 4th one now showing signs of going down hill similar to the others. They all seem to start with not or barely moving for a few days, but still alive, to not moving at all and seemingly dead a few days later.

Parameters seem fine, nitrates around 10 or less.

Is this normal?

Snail longevity depends on many factors, least of not which is the unknown of how old the snails were when you bought them. As you've already surmised, system parameters are another factor as is the area of origin (cool water vs. tropical trochus) as is the food supply. There is good information on Trochus snail here: https://www.algaebarn.com/utilizing-the-trochus-snail-trochus-spp

In summary-Algaebarn says:

Tropical species of Trochus are generally long lived when the environment is suitable with sufficient food supply. Algaebarn recommends: "Once these hungry snails have completely decimated the algal films, their diet should be occasionally supplemented with an algae wafer or two dropped in during evening hours."

A good site to help you identify the species: http://reefkeeping.com/issues/2004-05/rs/index.php

Reefkeeping suggests another reason for early demise as follows: "they often suffer significant damage during water changes or during transport from a dealer's to an aquarist's tank. The circulatory system of snails may be very complex (Figure 5), and many of its vessels and channels can rupture under stresses caused by changes in salinity. The vessels in the kidney are numerous and delicate, and may rupture if the animal is not slowly acclimated when being moved from one set of water conditions to another. If the acclimation is too fast, the animal will die in a few minutes to a few weeks. If the snails are drip acclimated, the acclimation time may need to be on the order of five to ten hours for maximal survival."

IMO, Trochus snails are hardy snails and live for years in my systems, but they're not as hardy as the ninja snails. I rarely replace ninja star snails. I've even seen ninja snails eat the dreaded Bryopsis algae once it was weakened with fluconazole.

Hope you figure out what is causing their early demise. ;Nurse