Anatomy & Physiology
Nervous system and Sense organs
Anomurans have intermediate level of cephalization within the varied degree of cephalization exhibited by decapods (Ruppert, Fox & Barnes 2004).The legs and antennae are important for the detection of the surrounding environment (Ruppert, Fox & Barnes 2004). Researches indicate the impact of ocean acidification on the flicking behaviors of antennae for olfactory sensing (De la Haye et al. 2011)
Feeding and Digestive system
Hermit crabs are mostly scavengers and feed on dead or dying animals (Poore 2007). The small limbs of the mouth part (maxillae and maxillipeds) manipulate and macerate the food, then it is ground up in the stomach, passed through a mostly straight gut towards the anus, which is located on the ventral side of the telson (Forest et al. 2000; Poore 2007).
Respiration
Hermit crabs have gills composed of lamellar plateswithin the lateral branchial chambers, which are protected by the carapace(Forest et al. 2000; Ruppert, Fox & Barnes 2004). The gills collectively divide the branchialchamber into two parts; water enters the inhalant chamber, passes through gills(where gas exchange occurs), and exit from exhalant chamber (Ruppert, Fox & Barnes 2004).
Circulatory system and Excretion
The hemal system of decapod crustaceans includes a heart, arterial system, capillaries, and venous sinuses (Ruppert, Fox & Barnes 2004). Oxygenis transported by hemocytes and hemocyanin in blood (Ruppert, Fox & Barnes 2004). Nitrogenouswastes are excreted across gills, and the nephridia regulate the ionconcentration (Ruppert, Fox & Barnes 2004).
Reproductive organs
Females have gonopores on coxae of third pereopod, while those of males are located on the coxae of fifth pereopods (Forest et al 2000). Males insert a spermatophore into the females’ gonophores, and the eggs are fertilized after they are laid and attached to the abdominal legs inside the shell of females (Poore 2007).
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