2012 COURSE DATES: AUGUST 4 – 17, 2012 - Sirenian International

Marine Hermit Crab
Clibanarius vittatus
Michelle Cassidy
Ecology and Behavior of Manatees and Dolphins in
Belize, Class of 2011
(contact: caryns@sirenian.org)
Taxonomy
Kingdom Animalia
Phylum Arthopoda
Class Crustacea
Order Decapoda
Family p
Genus Clibinarius
Species Clibinarius vittatus
Ecology
Common to most marine, estuarine, and
shoreline environments, hermit crabs can
be easily found worldwide. On Spanish
Lookout Caye in Belize, Central America,
both terrestrial and aquatic varieties of this
crab can be easily spotted; the former found
wandering the sandy shore, and the latter in
the muddy shallows of the mangrove
swamp. The mangrove species, C. vittatus,
feeds on plant and animal detritus that sinks
to the bottom.
Physical Description
Hermit crabs utilize shells (generally from
gastropods) for protection. This results from
their development of a non-calcified
abdomen that would make them vulnerable
to predation (Schejter & Mantelatto 2009).
Crabs have large foreclaws and smaller
hindclaws. Shell sizes and coloration vary
significantly between individuals.
Conservation
Though the hermit crab itself is not
endangered, human expansion threatens its
habitat. These crabs play a key role in the
Mangrove ecosystem via scavenging and
consuming detritus. In order to protect these
animals and the web of life they exist within,
it is important to conserve Mangrove
swamps, such as the ones on Spanish
Lookout Caye. Plenty of Mangrove Cayes in
Belize have been dredged and filled to
provide land for resorts, the process of
which destroys valuable Mangrove
resources and hermit crab habitats.
Promoting awareness of the numerous
species that depend on Mangroves for
survival is key to conserving these animals.
Behavior
Crabs retreat quickly into their shells at any
sign of potential danger. They will warily
emerge from their shells if not touched or
approached for approximately one minute.
Competition for particularly nutirient-rich
patches can become aggressive, with larger
crabs often strong-arming smaller
individuals into leaving the area, so they can
enjoy the food source (Ramsay et al. 1997).
Hermit crabs reproduce seasonally, with
intensive mating activity occurring in the
warmer months. Studies show that the
recruitment area for young crabs differs
from the adult habitat, and individuals are
already an intermediate size once they
appear. (Sant´Anna et al. 2008, Turra &
Leite 2000)
Crabs can detect chemical signals of a dead
or dying gastropod or conspecific, alerting
them to the presence of a potential home
(Rittschof 1980, Rittschof et al. 1992). They
can also use chemical stimuli to identify
predators (Rosen et al. 2009).