Rough Star Coral

Rough Star Coral, Isophyllastrea rigida on the left and Symmetrical Brain Coral, Diploria strigosa on the right. Source: http://www.livingoceansfoundation.org/photo/jamaica-photos/

Rough Star Coral, Isophyllastrea rigida on the left and Symmetrical Brain Coral, Diploria strigosa on the right.
Source: http://www.livingoceansfoundation.org/photo/jamaica-photos/

Rough Star Coral,  Isophyllastrea rigida is commonly found in the Atlantic Ocean along the shores of the Caribbean Islands, Bahamas and Florida. The fossil sample below is part of a collection gathered in the 70’s and 80’s during Florida vacations my husband’s parents took from their busy lives. Winkie, my mother-in-law (may she rest in peace) faithfully collected sea shells and coral adrift on the beaches, which today is not allowed. Now in my care, it has been my pleasure to research their origins and share them with you on the information highway which she never knew about, but would have been very proud to share.

Winkie with my late husband Joseph at age three

Winkie with my late husband Joseph at age three

Rough Star Coral is easily recognized by its small dome-shaped colonies and closely spaced corallites having only a thin margin between them and the polyps are rounded to polygonal in outline. Living colonies of the rough star coral range in color from varying degrees of light green to yellow, usually with the ridges being lighter in color than the darker groove floors.

rough star coral fossil_edited-1

Rough Star Coral (Isophyllastrea rigida)

 

It belongs to a family of corals called Mussidae originating during the Cenozic Era beginning 65 million years ago. Mussidae is a relatively small family of coral consisting of roughly 13 genera with a wide geographical distribution. Eight genera from Mussidae are found in the Indo-Malayan Western Pacific seas and the remaining four genera, including the Rough Star Coral, Isophyllastrea rigida are Atlantic species.

Below are living Mussidae corals from the genera of Acanthastrea, a showy and colorful breed with meaty polyps living in the Indo-Pacific regions. The similarities and differences from my Atlantic species, Rough Star Coral, Isophyllastrea, rigada, and Acanthastrea requires a close study to discern.

Acanthastrea lordhowensis

Mussidae (Acanthastrea lordhowensis)
Source: en.wikipedia.org

Acan IMAC QM

Mussidae (Acanthastrea)
Source: http://www.wetwebmedia.com/mussidae.htm

 

 

 

 

 

 

 

Acanthastrea

Mussidae (Acanthastrea) Source: http://www.wetwebmedia.com/mussidae.htm

CLASSIFICATION: ROUGH STAR CORAL

  • Kingdom: Animalia
  • Phylum: Cnidaria (stinging cells)
  • Class: Anthozoa (flower animal)
  • Subclass: Hexacorallia (polygon shape)
  • Order: Scleratina (stony coral)
  • Family: Mussidae (large fleshy polyps)
  • Genus: Isophyllastrea
  • Species: rigida

Coral: A Simple Animal Simply Explained

Corals exist at the tissue level lacking organs, such as a heart. On the evolutionary ladder, corals are one step above the sponges. They are the simplest animals to have a nervous system, and a connected muscular system, and a dedicated reproductive system.

A video beautifully photographed with vivid colors and depictions of the coral reefs geared for kids, but great for adults as well.

 

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Two Related Genus’s of Star Coral

Elliptical Star Coral

Elliptical Star Coral Fossil (Click to view large for fine details, then arrow back)

 

 

 

 

 

 

 

 

Because the variety of corals is so vast, it can be difficult  to identify species which requires a discreet eye. After close examination and research, I believe I have targeted its identity!

Elliptical star coral is named for its oval elongated shaped corallites or the calcareous cups from which the polyps protrude. Scientifically named Dichocoenia, stokesi, shown above, is a massive colonial coral that forms round humps up to 16 inch (40 centimetres) in diameter. These two characteristics coincide with my fossil quite well.

It is a fairly uncommon species, and has been placed on the Red List for Endangered Species. In 1995 off the Florida Keys, Dichocoenia, stokesi suffered from a disease called white plague which killed 95% of its colonies. It’s a slow growing variety for which the struggle to come back is fast diminishing, unless we humans do something about its plight and that of many other coral varieties.

Kingdoms : Animalia

Phylum:  Cnardia (Marine group with stinging cells)

Class:  Anthozoa (Flower Animal)

Order:  Scleratinia  (Modern species of Stony Coral)

Family:  Meandrinidae (meandering  form)

Genus: Dichocoenia (hump-forming or flattened corals with irregular calyces)

Species: stokesi (elliptical or pineapple star coral)

Blushing Star Coral Fossil

Blushing Star Coral Fossil (View Large)

Blushing Star Coral Fossil Side view showing flat plate form)

Blushing Star Coral Fossil
(Side view showing flat plate form)

 

 

 

 

 

Stephanocoenia, intersept  have tentacles that are commonly extended during daylight, unlike most coral. When touched, it rapidly retracts them causing a slight color change, which gives this coral its common name of “Blushing Star Coral”. It can be found in Florida, the Caribbean and Central American regions and as far south as Brazil. It’s found in a number of reef habitats including channels and lagoons. It grows massive encrusting colonies forming flattened domes. Corallites can be circular to polygonal. The two characteristics of flattened domes and corallite shapes are in line with my coral fossil shown above.

Nutrition: Like all coral, it has a symbiotic relationship with algae zooxanthellae. Through photosynthesis, the algae provides energy to the coral which in turn homes the algae. Food is caught as it passes by the coral tentacles whereby stinging cells called nematocysts stun and hold onto it.

Its earliest fossil record dates back to the Eocene period between 55 and 33 million years ago.

The Blushing Star Coral is also susceptible to white plague type II which exposes the skeleton by rapid tissue destruction and is also on the Red List of Threatened species.

star coral blushing 3

Blushing Star Cora. (View Large)
Source:
http://reefguide.org/carib/pixhtml/blushingstarcoral2.html

Kingdoms : Animalia

Phylum:  Cnardia (Marine group with stinging cells)

Class:  Anthozoa (Flower Animal)

Order: Scleratinia (Modern species of Stony Coral)

Family:  Astrocoeniid  (small family made up of  both reef building and non reef building  genus, both with and without symbiotic zooxanthellae as well as both branching and encrusting species.

Genus: Stephanocoenia (Colonies are flattened usually with regular, smooth surfaces. Corallites are small and the wall between them may be relatively wide.)

Species: intersepta