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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Maze Coral or Is It Rose Coral

Judging from the title of this article, you may have gathered their can be confusion identifying coral fossils and you would be right. All corals are not single organisms, but rather are a colony of individuals we know as polyps (the jelly like part). The polyps band together and slowly build a calcium carbonate skeleton. Herein lies the physical diversity of corals as each species builds a slightly different style of skeleton.

I feel fairly confident I have several maze coral fossils in my possession inherited from my mother in law, Winkie’s, collection. They are commonly found in the Bahamas, Caribbean and Florida shores where she discovered them lying on the beaches during family vacations in the 60’s and 70’s.

Can you tell the difference between the maze coral and the rose coral below?

Rose Coral Fossil

Maze Coral Fossil

While searching, I realized that maze corals are sometimes lumped together with brain corals or are even called maze brain corals.  The most distinguishing features from other brain corals is that the maze brain coral have thicker convoluted ridges and well defined plates. Also, there is an indentation running along the crest of the walls where the adjoining plates “corallites” meet. Colonies form both flat heads and or hemispherical plates which fits the description of the one in the photo above.

CLASSIFCATION

  • Kingdom: Animalia
  • Phylum: Cnidaria (Animal with stinging cells)
  • Class: Anthozoa (Flower like animals)
  • Subclass: Hexacorallia (corals having parts in multiples of 6)
  • Order: Scleractinia (Stony Skeleton)
  • Family: Meandrininidae (Meandering Colony Corals)
  • Genus: Meandrina (forms massive hemispherical heads or have large flat plates and can grow to a metre (yard) across)
  • Species: M. meandrites
Rose Coral Fossil (Shows Cone Shape Underside)

Rose Coral Fossil
(Shows Cone Shape Underside)

Rose coral, Manicina, areolata,  often have irregular cone shaped undersides and at times consist of a short stalk which can be unattached to the substrate. The most common rose corals forms elliptical or oval colonies (shone below) with a long continuous central valley and several short side valleys.

Colors: Yellowish-brown, tan or dark brown, often with the valleys and walls being contrasting colors. Like most corals, the polyps are only extended at night and are often green.

Manicina areolata Rose Coral Fossil

Manicina areolata
Rose Coral Fossil

Manicina areolata Rose Coral Fossil (Underside)

Manicina areolata
Rose Coral Fossil (slight cone shaped underside)

Interesting Behavior

Manicina areolata is one of only a few corals that can be actively mobile depending if its the colony form.

If a small colony gets turned over it gorges its stomach with water to become bloated, and then jets water from one side at a time. This causes a back and forth rocking motion until the center of gravity shifts, allowing it to rapidly flip upright. The entire process takes a few hours until the final flip occurs in an instant. Larger colonies are more likely to die by smothering in the sediments placing a limit on the size any given colony can grow.

Second Growth Form (Hemispherical)

Manicina, areolata rose coral occurs in two distinct grow patterns making matters even more confusing. The second form consists of semicircular heads with  flattish undersides, winding wide valleys and ridges forming irregular furrows. 

Manicina aerolata Source: http://reefguide.org/carib/rosecoral.html

Rose Coral Manicina aerolata
Source: http://reefguide.org/carib/rosecoral.html

Rose Coral Fossil

Rose Coral Fossil

Habitat: Rose coral Manicina, aerolata is very abundant off the Floridian shores as well as the Bahamas and Caribbean. It prefers shallow, productive, near shore habitats characterized by abundant sediments such as seagrass meadows, or along the fringes of mangrove forests.

CLASSIFICATION

  • Kingdom: Animalia
  • Phylum: Cnidaria (Animals with stinging cells)
  • Class: Anthozoa (Flower Animal)
  • Order: Scleractinia (Stony Skeleton)
  • Family: Faviidae (generally spherical shape and grooved surface which resembles a brain)
  • Genus: Manicina
  • Species: M. areolata

The genus Manicina sp. includes over 10 species, but Manicina areolata is the only species that survives today. The heyday for Manicina was during the Miocene and Pliocene eras between (24 million to 1.6 million years ago). About one million years ago, approximately half the species of reef corals living in the Caribbean became extinct.

Low Relief Lettuce Coral

Low Relief Lettuce Coral Fossil (Agaricia, humilis)

Low Relief Lettuce Coral Fossil (Agaricia, humilis)

Low relief lettuce coral is common in the open seas of the Caribbean, Bahamas and Florida, often scattered among other corals in inner bays and sometimes on mangrove roots. It can thrive from shallow sea levels to the lower depth limits of the reef, approximately 60 meters deep. This species has a widespread distribution. It shows a number of growth forms. It can appear saucer like on cliff sides or small half moon shaped in shallow depths. In depths deeper than 10 meters, the coral forms broad vertical scales with corallites on one side only.

CLASSIFICATION:

  • Kingdom: Animalia
  • Phylum: Cnidardia (C is silent) Marine group with stinging cells
  • Class: Anthozoa – Flower Animal
  • Order: Scleratinia – Reef building stony corals
  • Family: Agariciidae – includes cactus coralselephant skin coralsplate corals and lettuce corals. Members of the family include symbiotic algae called Zooxanthellae in their tissues which help provide their energy
  • Genus: Agaricia – lettuce corals
  • Species: humilis – low relief
Winkie, Joe, Johnny and Joey

Winkie, Joe, Johnny and Joey

 

 My mother in law Winifred (Winkie) loved collecting coral during Florida vacations in the 60’s and 70’s.  My late husband, Joseph, came from a hard working family in the 50’s living in Detroit. His dad, Joseph, was a designer for Chrysler Corporation and designed an amphibious vehicle used in WWII.    

I feel honored to have samples from her coral collection and am excited to share it with you. She would have been thrilled by this.