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Pterois volitans
Pterois volitans is commonly known as the red lionfish. This species of fish is native to the Indo-Pacific reefs, but due to aquarium dumping, they have become an invasive species in the Caribbean and Atlantic Ocean. They have been able to thrive and grow in such numbers for a wide range of reasons. First, they have no natural predators in that region, therefore there is nothing to controlling the population. Another reason is that they are a voracious predator, meaning that they will eat just about anything that is available to them. Also, they have a collection of venomous spines that contain a neurotoxin, which they use as a defense mechanism.
The role lionfish play in the coral reef ecosystem is that they are predators. They feed on other organisms, thereby acting as a natural regulator of population size. However, the issue with this species is that in the locations where they are considered invasive, there are few predators to control their own populations. As a result, the lionfish population continues to increase, while the population of other species continues to decline. So, while their ability to control population sizes can be a productive function, it can also be a downfall when their own population is unable to be kept in check.
Red Lionfish females are able to release thousands of eggs at a time during spawning, which usually occurs at or around the surface. These spawning events occur every three to four days, significantly increasing the probability that they will be fertilized. When the eggs are released, the male lionfish move to fertilize them. The eggs of one female may be fertilized by more than one male. After approximately a day and a half, the eggs will hatch and begin to grow, spending about a month in the pelagic zone. One of the reasons lionfish populations are able to have such great success is because they grow and mature so quickly. This makes them less likely to become prey in the early stages of their lives.
The most significant adaptation of lionfish is their spines. These spines provide a defense mechanism that plays a key role in their survival. They are also pointed towards the caudal fin which means that predators must attack it from the front. Those spines are able to be moved up and down, and side to side, allowing them full utilization of their defense.
Amphiprion ocellaris
Also known as Clown Anemonefishes (more commonly known as the Clown Fish). They get their name from their bright colors and behavior. There are 11 dorsal spines and 17 pectoral rays that make it different from the closely related Amphiprion percula, and in this species, the females are usually larger than the males.
There have been more than 30 identified clownfish species and their colors vary as well.
Most anemonefish can be found in shallow water reefs or sand. They are distributed throughout the Indian Ocean, Red Sea, South East Asia Region, northern Australia, and the Western Pacific. They are rare to the Caribbean, Mediterranean or the Atlantic Ocean.
They have a special symbiotic relationship with sea anemones. For Clownfish, sea anemones are a source of protection and shelter against predators because of the sea anemones's nematocysts. In return (and as part of it's role in the ecosystem), the Amphiprion ocellaris is a predator for anemones. They can protect the anemones by removing parasites that they find on the anemone.
The spawning season of clownfish is year round in tropical water and in nature it seems to be linked with the lunar cycle. When the Amphiprion ocellaris hatches, it enters a short larval stage where it stays close to the surface in a planktonic stage from eight to 12 days. While transforming from larvae to fish, it will move towards the bottom and search for a host anemone to inhabit. The Amphiprion ocellaris is part of the subfamily Amphiprioninae (aka anemonefishes) which are hermaphrodites (develop first into males and possibly into females in the future).
"Clownfish — National Geographic Magazine." Clownfish — National Geographic Magazine. Accessed March 06, 2017. http://ngm.nationalgeographic.com/2010/01/clownfish/prosek-text/2.
"Coral Bonus: Geographic Variants Within Clownfishes - Maroons, Ocellaris & Perculas - (Part 6b)." Reef To Rainforest Media, LLC | CORAL Magazine | AMAZONAS Magazine | Microcosm Publishing. Accessed March 06, 2017. http://www.reef2rainforest.com/2014/12/18/coral-bonus-geographic-variants-within-clownfishes-maroons-ocellaris-perculas-part-6b/.
Danoff-Burg, Dr. James A. "Invasion Biology Introduced Species Summary Project - Columbia University." Invasion Biology Introduced Species Summary Project - Columbia University. Colombia University, n.d. Web. 06 Mar. 2017. <http://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/Pterois_volitans.html>.
Liquid. "Aquarium Fish: Reproduction and rearing of ocellaris clownfish (Amphiprion ocellaris) in captivity." — Advanced Aquarist | Aquarist Magazine and Blog. May 07, 2009. Accessed March 06, 2017. http://www.advancedaquarist.com/2007/2/fish.
Raines, Ben. "Red Lionfish." Red Lionfish - Interesting Fishes of the Gulf of Mexico and Coastal Mississippi. University of Southern Mississippi, 23 June 2014. Web. 06 Mar. 2017. <http://gcrl.usm.edu/public/fish/red.lionfish.php>.
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