deathmatch782 said:
conch
the snout and the leg give it away
they are great algae and detrius eaters i have one in my 75
MOST of the conch or conch-like snails are algae and detritus eaters, however there are a few genera that are similar in appearance that are predatory carnivores...
True Conchs are members of the Family
Strombidae, and are strictly herbivorous. Within this family are several genera, including the genera
Strombus (the true Conchs),
Lambis (the spider conchs),
Tibia spp. (tibias),
Varicospina (beak shells) and the
Tterebellum spp.. Even though these all have different morphologies, there are certain internal structural traits that tie all these togehter as a taxonomic group. However, there are many similar genera of the carnivorous whelks, in particular to the genus
Strombus that so closely resemble the herbivorous snails that they are frequently misidentified as such. Their shells are both tapered at each end with the front end elongated out into a calcareous spout or siphon. The only real means of differentiating these different snail groups is to study their fine morpohology and behavior. When the snail in question extends its snout/probiscus from its shell, look closely for the eyes, in particular for the presence or absence of eye stalks. In all of the animals in the herbiverous conch group, the eyes quite evident, with long stalks, visible eyeballs, and observable pupils. In the predatory whelks, the eyes are typically located at the base of the sensory tentacles at the top of the head, usualy present as small black dots in the flesh of the head. The conchs have a long protruding proboscis which they use to bite off chunks of algae wheras the whelks usually hqave short snouts and a rasping "licking" means of feeding. In a very real sense, conchs are not rasping grazers but biting algae eaters, a task at which they excel. From your description of both the locomotion, the photos, and the general behavior or your specimen, I think your snail is safe for the tank, however, I would still watch it for a while, just to make sure...
All strombids are animals of the sand and have a small muscular foot which is not adapted to crawling on rocks. They actually move by lurching or jumping, termed
saltutory locomotion. This mode of locomotion is good for moving through sandy sediments, but is inefficient and largely ineffective as these snailis grow to sizes above 2 to 3 cm when moving on rocks. This results in these creatures staying in the sand once they reach some size. For this reason, the conchs usually require a sand bed with some depth to it to successfully curate these mollusks. Generally, as a rule of thumb, there should be about one to two square feet of open sand with some algae coverage per inch of snail shell length. Conchs will move around in the sand at the bases of the live rock while foraging and remove algae from quite high up on the rocks using their proboscus while their bodies are still buried. These snails are quite entertaining to watch, although you may need to stay up late at night to see some of their behaviors.
The Queen Conch,
Strombus gigas, will grow to quite large sizes given enough algae, with adults reaching sizes of up to 40 to 50 cm. Growth rates of up to 3cm a month in captivity have been reported when adequately fed. However, this often results in the snail becoming so large that it outstrips the ability of a system to supply adequate nutrition, and the conch dies from starvation. Other smaller conchs are equally good at grazing on algae, and should be purchased instead of the queen conchs. Several of the smaller conchs, such as the Florida Fighting Conch,
Strombus alatus, are much better suited for the janitorial role we assign these creatures. These conchs have the habit of disappearing under the sand for extended periods, actually moving along under the surface of the sediments eating algae. Occasionally they may stay in one place, using their proboscis to forage in the sediments up to several cm from their stationay position. Although they MAY seem to be totally covered by the substrate, they extend their eyes to or slightly above the sediment's surface, such that through careful inspection one can find them by searching the sediment for the telltale eye stalks.
For more info on conchs vs whelks, see:
http://www.gastropods.com/Taxon_pages/Family_STROMBIDAE.html
http://www.sms.si.edu/irlfieldguide/Melong_corona.htm
http://www.wetwebmedia.com/snailcompfaqs.htm
for some thumbnail pix for attempts at better ID, see
http://www.gastropods.com/Taxon_pages/Family_STROMBIDAE.html
HTH
