juvenile fish among branches
seriatopora hystrix hermaphrodite, mature polyps producing both sperm , eggs. sperm liberated sea , drawn other polyps of same or other colonies, , developing larvae brooded maternally. self-fertilisation may important strategy species. when released, larvae settle within 24 hours suggests limited dispersal range. many settle within few tens of metres of parent colony, others swept along in warm currents , end further afield. s. hystrix zooxanthellate species of coral, housing symbiotic dinoflagellates within tissues. has been found these symbionts transferred during brooding of larvae , different species of symbiodinium associated coral in different parts of range, example of coevolution , specialization.
another means of reproduction asexual means; fragments of coral become detached branches can form new colonies if deposited in suitable locations. @ times of stress, form of asexual reproduction takes place may allow of polyps survive though parent colony dies. has been termed polyp bail-out , involves growth of coenosarc (the living tissue covering skeleton) isolate polyp, detachment of polyp, , settlement of polyp on seabed followed attachment , growth of new skeleton. in laboratory, 5% of these polyps survived found new colony. coral exhibits high growth rate, high reproductive output , short life-span. successful species , first scleractinian coral colonise disturbed area.
the tangled bushy form of coral provides suitable habitat other animals. number of symbiotic decapod crustaceans find shelter , protection here , obtain food in form of mucus secreted coral. 2 species of alpheid shrimps , 3 species of xanthid crabs thought obligate symbionts , not found living anywhere else. coral benefits presence may attack , prevent predators feeding on coral. 1 coral colony house single species of symbiotic crustacean, including both adults , juveniles, large colony may house 2 species.
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