Download This Sample
This sample is exclusively for KidsKonnect members!
To download this worksheet, click the button below to signup for free (it only takes a minute) and you'll be brought right back to this page to start the download!
Sign Me Up
Table of Contents
Fascinating little critters, Hermit Crabs are decapod; they are ten-footed crustaceans of the superfamily Paguroidea, divided into two groups – aquatic and terrestrial. Made up of around 1100 species, Hermit crabs are known for their asymmetric abdomens in a scavenged mollusc shell.
See the fact file below for more information on the Hermit Crabs or alternatively, you can download our 20-page Hermit Crab worksheet pack to utilise within the classroom or home environment.
Key Facts & Information
BIOLOGICAL DESCRIPTION
- Hermit crabs have long, well-arched abdomens, which are soft, unlike the calcified bodies of related crustaceans. The defenseless abdomen is guarded from predators by a scavenged empty seashell carried by the hermit crab.
- Usually, hermit crabs make use of shells of sea snails, including those of bivalves (marine and freshwater molluscs that possess laterally condensed bodies inside a shell with two hinged parts), scaphopods (tusk shells or tooth shells), and hollow pieces of wood and stone.
- The terminal end of a Hermit crab’s abdomen is crafted to strongly grasp onto the columella or pillar of a coiled snail shell.
- Generally, hermit crabs are nocturnal.
MARINE HERMIT CRABS
- Marine Hermit crabs are aquatic animals, mostly found underwater in different depths of saltwater from shallow reefs to deep sea bottoms.
- The Clibanarius fonticola is the only species of marine Hermit crab. It lives in the freshwaters of Espiritu Santo, Vanuatu. Adult Hermit crabs of this species take the shells of Clithon corona.
- As pets, marine Hermit crab species are commonly kept in reef fish tanks.
- They use their gills to breathe underwater.
- In a short period of time, some can survive out of water, as long as their gills are damp.
LAND HERMIT CRABS
- Land Hermit crabs live as terrestrial species, found in tropical areas, even though they return to bodies of water to maintain their gills’ moisture, to live, and to reproduce.
- These group of Hermit crabs fall under the family Coenobitidae, with approximately 15 species of genus Coenobita.
- These land Hermit crabs are commonly kept as pets: Caribbean Hermit crab (Coenobita clypeatus), Australian land Hermit crab (Coenobita variabilis), Ecuadorian Hermit crab (Coenobita compressus), Coenobita brevimanus, Coenobita rugosus, Strawberry Hermit crab (Coenobita perlatus), and the Passionfruit Hermit (Coenobita cavipes).
SHELLS AND SHELL COMPETITION
- Hermit crabs need bigger shells as they grow. They compete with each other when scavenging because of the scarcity of gastropod shells.
- Empty shells depend on the relative abundance of gastropods that match the size of scavenging Hermit crabs. The population of organisms that feed on gastropods and leave the shells intact is also a biological issue faced by Hermit crabs.
- A group of hermit crabs may compete with each other to obtain the shell they favor. However, this may not occur when Hermit crabs in an area differ significantly in size. Those with tiny shells cannot grow as fast as those with perfectly fitted shells, and have high tendencies of being preyed upon by other creatures if they cannot retract thoroughly into the shell.
- Hermit crabs abandon and look for new shells as they grow in size.
- Both marine and land species observe a vacancy chain when swapping shells.
- Vacancy chain is a social structure where in the first in line crab leaves behind its own shell as soon as it finds a new empty shell. It first inspects the shell and, if is found to be too large, the crab returns to its own shell and waits with the others in a queue, arranged from the largest to the smallest crab.
- As soon as the first crab finds the right shell for its size, it claims the vacant shell, abandoning its old shell. All the crabs in line quickly exchange shells in sequence, each one transferring to the next size.
- There are times when sea shells are scarce and hermit crabs resort to alternatives, such as soda cans or other kinds of debris or even customized shells.
DEVELOPMENT AND REPRODUCTION
- Hermit crabs vary in size and shape, from species with an exoskeleton only a few inches long to Coenobita brevimanus, which can live for up to 70 years and can reach the size of a coconut.
- The Coconut crab (Birgus latro), a land hermit crab, is the world’s largest terrestrial arthropod, weighing up to 4.1 kg (9.0 lbs) and reaching up to 1 m (3 ft 3 in) in length from leg to leg.
- The first two stages of young hermit crabs, protozoa and nauplius, develop inside the egg. Larvae hatch at the third stage called the zoea, where in the crab grows a number of long spines, a long narrow abdomen, and an antennae. After various zoeal moutls, the final larval stage occurs, the megalopa.
CLASSIFICATION
- Hermit crabs are not true crabs (Brachyura); they are more similar to squat lobsters and porcelain crabs.
- There are six families acknowledged in the superfamily Paguroidea, with over 1,100 species in 120 genera. These include Coenobitidae (two genera: land hermit crabs and coconut crab), Diogenidae (20 genera of “left-handed hermit crabs”), Paguridae (76 genera), Parapaguridae (10 genera), Parapylochelidae (two genera), Pylochelidae (9 genera of “symmetrical hermit crabs”), and Pylojacquesidae (two genera).
Hermit Crab Worksheets
This is a fantastic bundle which includes everything you need to know about the Hermit Crabs across 20 in-depth pages. These are ready-to-use Hermit Crab worksheets that are perfect for teaching students about the Hermit Crabs which are decapod; they are ten-footed crustaceans of the superfamily Paguroidea, divided into two groups – aquatic and terrestrial. Made up of around 1100 species, Hermit crabs are known for their asymmetric abdomens in a scavenged mollusc shell.
Complete List Of Included Worksheets
- Hermit Crab Facts
- Hello Hermit
- Hermit Crab Anatomy
- Hermit Crab Basics
- Life of a Tiny Critter
- Asking a Hermit Crab
- Best of Both Worlds
- Hermit Crab Gallery
- House for Hermits
- I Want One! Or Do I?
- Hermits as Pets
Link/cite this page
If you reference any of the content on this page on your own website, please use the code below to cite this page as the original source.
Link will appear as Hermit Crab Facts & Worksheets: https://kidskonnect.com - KidsKonnect, March 11, 2020
Use With Any Curriculum
These worksheets have been specifically designed for use with any international curriculum. You can use these worksheets as-is, or edit them using Google Slides to make them more specific to your own student ability levels and curriculum standards.