1-17-12  White-spotted Jelly from Ron’s Jellies Series

Kingdom: Animalia,  Phylum: Cnidaria,  Class:Scyphozoa,  Order: Rhizostomae,   Family: Mastigiidae

Phyllorhiza punctata   

DISTRIBUTION:  Native to Southwestern Pacific and introduced widely. 

HABITAT: P. punctata is a coastal and estuarine jellyfish.

APPEARANCE; P. punctuate is a large jellyfish with a rounded and somewhat flattened gelatinous bell that is clear or possibly tinted brown with many small white crystalline refractive spots close to the surface. As is characteristic of members of Order Rhizostomae, the bell margin lacks tentacles and the central mouth area is ringed by eight highly dichotomous (branching) oral arms that each bear 14 lappets (flaps of tissue) and become fused near their bases.  Within it’s native range and in certain introduced localities, symbiotic zooxanthellae reside in the tissue of the animal, giving these jellyfish a brownish tint.

DIET: Like most members of Phylum Cnidaria, the tentacles of Phillorhiza are equipped with stinging cells called cnidocytes. Within these cells are stinging organelles called nematocysts. When discharged, nematocysts can immobilize small prey items that are subsequently ingested. Nematocysts are also used as a defense mechanism. The planktonic egg and larval stages of several fish species (including commercially important species such as red snapper in the gulf of Mexico) are probably important as prey items.  Additionally, throughout its native range and much of its introduced range, P. punctata also harbor endosymbiotic zooxanthellae within their bell. In a relationship analogous to that of reef-building tropical corals and their resident zooxanthellae, primary production of the photosynthetic zooxanthellae likely fulfills a large proportion of the nutritional needs of the host jellyfish.   

REPRODUCTION and DEVELOPMENT: Scyphozoans have a life cycle that can be broadly divided into two parts: a free-living medusa and an attached, sessile polyp stage.  Sexes are separate in the medusae and these produce haploid gametes that combine through external fertilization to form free-swimming planula larvae.  Planulae search out suitable settlement sites and leave the water column to assume a sessile benthic existence.  Once on the bottom a polyp form occurs and this form reproduces asexually by “cloning” or dividing itself into other polyps. These polyps or scyphistomae then give rise to new offspring in the form of free-swimming medusa.  Jellyfish can live for up to five years in the polyp stage and up to two years in the medusa stage.

REMARKS: An invasive species now found in the Caribbean, Hawaii, and southern Brazil.  Phyllorhiza consumes large amounts of small zooplankton (including fish eggs and larvae) and directly impacts the shrimp industry because nets were becoming clogged with jellyfish.  (after Smithsonian Marine Station at Fort Pierce)  

LOCATION: Color Cluster 1-17-12

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