Date & Time : 16, December 2018 05:28
Phylum - Cnidaria
Class - Hydrozoa
Order - Milleporina
Genus - Millepora
These are found in tropical seas of West Indies and U.S.A., often associated with coral reefs.
Colonial marine coral found in shallow water.
- Colony consists of branching calcareous growths up to 30-60 cm in height and is white or yellowish in colour.
- Epidermis secretes a calcareous perisarc which forms a braod base through which it is attached to the rocks.
- The body surface contains innumerable pores which are of two types:
- large gastropores; separated by each other by a distance of 1-2 mm
- small dactylopores, distributed irregularly
- Colony have 2 kinds of zooids - gastrozooids and dactylozooids.
- Gastrozooids are nutritive zooids which protrude through gastropores. These are shorter and have a mouth surrounded by 4-6 tentacles.
- Dactylozooids or protective zooids arise from dactylopores. These are longer, slender and are devoid of mouth. They are provided with short tentacles beset with batteries of namatocysts.
- Medusae or gonophores are minute which do not have mouth and tentacles. They bud off directly from the coenosarc and are present in calcareous rounded chambers called ampullae.