The
Virgin Nerite, Neritina Vittina virginea
Virgin
nerites occur in the Caribbean, Gulf of Mexico
including Texas, Florida, and the South Atlantic.
The color and pattern in Neritina Vittina
virginea is extremely variable. Colors include
purple, red, orange, gray, black, white and patterns
with checkers, triangles, or stripes. There are
numerous Neritina species found in coastal habitats
in tropical and temperate locations all over the
world, and many of them are superficially identical
to N. virginea. Neritina communis
(Quoy & Gaimard, 1832), now known as Vittina
waigiensis (Lesson, 1831) from the Philippines
and western Pacific is even more colorful than
the Virgin Nerite and just as variable in pattern.
The Virgin nerite occurs at the low tide mark
on mudflats and Halodule spp. seagrass
beds, often in areas with brackish water. It also
occurs in tidepools along with the similar looking
Puperita pupa tristis. The operculum
in the Virgin nerite is darker than the operculum
in Puperita, otherwise they can be difficult
to distinguish. The diet and husbandry requirements
in captivity are the same as for Puperita.
The life span in captivity is also typically about
one year. Other species in the genus Neritina
may live for longer periods of time. Vittina
luteofasciata, from the central American
Pacific coast lives at least three years in captivity
(pers. obs.). It has recently been imported to
the USA for the aquarium trade.
Bleeding
Tooth, Nerita peloronta
The
Bleeding Tooth nerite gets its name from a strange
formation at the aperture of the snail that looks
just like a set of teeth surrounded by a blood
red stain. The "blood" is really just
iron deposited in the shell, and the function
of the teeth is not known, but it seems that the
bleeding teeth are intended as a display that
makes the snail shell appear to be a mouth. Presumably
this would startle potential small predators.
The bleeding tooth nerite reaches up to 3 cm in
length. Its shell is yellowish with red and dark
purple zigzag marks. It is a pretty snail, but
unfortunately not suitable for home aquariums.
It lives just above the tide line and migrates
with the change in the water level. This results
in it escaping from the aquarium and ending up
somewhere else in your home, attached to a wall,
a bedpost, the ceiling. The surprising thing about
them is that they can remain out of water for
extended periods of time, days at least, possibly
weeks. I know this because I at one time attempted
to keep a few of them. After a few had become
missing in action, when I discovered them more
than a week later somewhere in the house, they
miraculously came back to life when placed in
a cup of saltwater. It might be possible to maintain
this snail in a large rocky tidepool exhibit,
but the tidal variance should be at least one
meter.
The
four tooth nerite, Nerita versicolor,
is very similar to the bleeding tooth nerite viewed
from above, but lacks the "blood" stain
on the underside of the aperture. It only reaches
2.5 cm in length. The four tooth nerite has 4
prominent teeth, compared to two or three for
the bleeding tooth nerite. It occurs in the same
habitat as the Bleeding tooth, but spends more
time in the water, and stays lower down on the
rocks even when it crawls out. Like the Bleeding
tooth it always crawls out of the water, so it
is not suitable for most aquariums. Lower down
on the rocks and in tidepools in Florida and the
Caribbean one may find the checkered nerite, Nerita
tesselata, that reaches 2 cm in length. Its
shell is checkered black and white and it may
have very small, modified teeth (Kaplan 1988).
The checkered nerite population includes individuals
that frequently crawl out of the water and individuals
that rarely do. They are distributed on the rocks
and in tidepools according to their preference.
To the best of my knowledge no-one has studied
the difference in their behavior, but I have observed
it because it is my experience that the ones that
rarely leave the water are suitable for aquariums
while the ones that frequently leave the water
are not, even though they are technically the
same species. The water-loving form often has
coralline algae on its shell, a telltale sign
of its preference to remain in the water. It is
a good herbivore for marine and reef aquariums.
Another
nerite that occurs in Florida and the Caribbean,
especially on rocks near mangroves, is Nerita
fulgurans. Its shell is black and it has
prominent concentric grooves. As with the checkered
nerite, some members of a population spend more
time in the water than others. In general, however,
Nerita fulgurans will eventually migrate
out of the aquarium so I don't recommend it.
Emerald
nerite snails Smaragdia viridis
Emerald
nerites belong to the genus Smaragdia.
They are small and flattened, with thin shells
that are translucent and bright green. This color
makes them nearly invisible on the seagrass blades
where they live. It would be a dream if these
exquisite little snails fed simply on epiphytic
algal films on the grass, but unfortunately their
diet consists not of algal films but of the seagrass
itself! They pierce the cells of the grass and
draw out the contents, leaving clear spots on
the blades. Therefore they are not suitable for
most aquariums. Without their seagrass food source
they starve within a few weeks.
Nerita
picea Récluz, 1841.
In
Hawaiian tidepools there is a little black nerite
that evolved to match the color of lava. It is
a very hardy little herbivore, available to the
trade from Indo Pacific Sea Farms. They feed well
on diatoms and are active during the day. The
lifespan in captivity is typically about 1 year.
Nerita
polita and Nerita albicilla from
the Western Pacific and Red Sea are occasionally
offered for sale to aquarists. They have elongated
shells that are colored cryptic shades of gray
and brown. Nerita sanguinolenta Red Sea
and Eastern Mediterranean is similar. These nerites,
which reach a size of about 3 cm are long-lived
(3 years or more) excellent herbivores for reef
aquariums, feeding even on Derbesia (green hair
algae).
While
not yet as well established as turban snails for
the “cleanup crew” in reef aquariums,
nerites do have many fans and are gaining in popularity.
Considering how prolific nerites are in their
natural habitat and how frequently they lay eggs,
they would seem to be an ideal candidate for captive
propagation. Tropical mariculture farms have succeeded
in culturing turban snails (Trochus,
Turbo, Astraea) as herbivores
for aquariums. It would be worthwhile to investigate
the special requirements for successful captive
rearing of nerites.
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Vittina
luteofasciata from the pacific coast
of Central America is a beautiful and
hardy herbivore, shown here at Quality
Marine in Los Angeles.
The
Checker Nerite from Florida and the Caribbean
is a good herbivore for aquariums, only
occasionally crawling above the water
line.
The
habitat of the Bleeding Tooth Nerite,
Nerita peloronta, is just above
the tide line on rocky shores. For this
reason it crawls out of aquariums.
A
comparison of the undersides of Neritina
(Vittina) virginea and Puperita
pupa trisitis. Puperita
has the lighter colored operculum.
A
comparison of the same two snails viewed
from above. |
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