''Rhytisma fulvum'', the sulphur leather coral, is a
species of
colonial
Colonial or The Colonial may refer to:
* Colonial, of, relating to, or characteristic of a colony or colony (biology)
Architecture
* American colonial architecture
* French Colonial
* Spanish Colonial architecture
Automobiles
* Colonial (1920 a ...
soft coral in the
family . It is native to shallow reefs in the
Red Sea and the
Indo-Pacific
The Indo-Pacific is a vast biogeographic region of Earth.
In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...
region. It was
first described by the Swedish naturalist
Peter Forsskål in 1775.
Description
''Rhytisma fulvum'' is a
zooxanthellate species and has two different colour morphs, yellowish-brown and grey. There is no
taxonomic
Taxonomy is the practice and science of categorization or classification.
A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...
difference between these forms.
It is an encrusting species forming sheets over the
substrate
Substrate may refer to:
Physical layers
*Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached
** Substrate (locomotion), the surface over which an organism lo ...
which may mesh together. The polyps are small and packed together in rows, each raised on a cone-shaped peduncle.
[
]
Distribution and habitat
''Rhytisma fulvum'' is native to the Indo-Pacific region. Its range extends from the Red Sea, Zanzibar and Madagascar, to Indonesia, Papua New Guinea and the Great Barrier Reef in Australia.[
]
Ecology
''Rhytisma fulvum'' is a dioecious
Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproductio ...
species of soft coral, colonies being either male or female. In the Red Sea, breeding takes place from late June to early August. By this time, the oocytes have been maturing for about ten months and the sperm sacs for seven months. Male colonies liberate sperm into the water column in a spawning event synchronised with the phase of the moon, with shallow-water colonies spawning earlier in the year than deep-water ones. Fertilisation takes place inside the cavities of the polyps in female colonies. The embryo
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...
s are then brooded on the surface of the colony, entangled in a sticky mucus. After about six days, the planula larvae have completed their development and are liberated and soon settle on the seabed. Each polyp in a female colony produces about twenty eggs, which is a relatively low number, but this is compensated for by the brooding process which maximises the chances of the developing larvae avoiding predation.[ The appearance of this seaslug closely resembles the surface of the coral, its gills even mimicking the feeding polyps, and this makes it very well- camouflaged.][ Its presence is revealed if the coral is touched, because this causes the polyps to retract and the nudibranch's presence is exposed. About a quarter of the corals of this species investigated were found to harbour this nudibranch.][
]
References
{{Taxonbar, from=Q2105025
Alcyoniidae
Animals described in 1775
Taxa named by Peter Forsskål