Last Updated on 02/15/2024

Some starfish are very welcome additions to the aquarium. They are generally detritavores and add a splash of color and character to our reef system. There are the oblivious star fish that you won’t see at your local fish store that are a nuisance to the reef. The Crown of Throne’s Starfish for example with ten to twenty arms covered in long sharp spines. Touching this guys will pack a sting. They pummel established reefs nondiscriminatory eating tissue of every stony coral in its path.

Most of us may have been duped into adding a chocolate chip star fish (protoreaster) to our reef early on, only to wake up and see them devouring a nice new gorgonia. They will consume clams and other invertebrates as well. Stars like this Giant Green, Brittle will go after fish, and become fairly large and destruct full once reaching maturity. Other Brittle Stars are very useful in the reef, consuming mainly detritus, but they are opportunist and will scavenge for food left over from a fish feeding. Actually if they get hungary enough you may see a wrestling match over some shrimp pellets.

One of the starfish of recent concern appearing on the scene a bit more often is the Asterina Anomala. The starfish is small only about 1/2 inch across and very hardy in the aquaria. They reproduce often to plague proportions by fission. These species are commonly imported on live rock, and initially believed to consume algae but more recently have been observed eating coral tissue. The animal seems to have no particular discrimination towards any one species and has been observed eating corals like Euphyllia , Lobophyllia, Stylophora, Seriatopora, Acropora and even Blastomussa. Removal of these starfish from your captive reef should be top priority. They are nocturnal feeders and are most likely hiding away in the afternoon hours. You can remove them manually with the use of a small tool such as tweezers. You could also introduce a natural predator like the Harlequin shrimp. Keep in mind this shrimp will enjoy you useful Brittle stars as well as these coral eating starfish. Quarantine of new additions will help you in this circumstance as well. You can keep the appropriate predators in your quarantine tank and be ready to eradicate this harmful species before you introduce it to your captive reef system.

Unveiling the Mysteries of the Asterina Starfish

Welcome to a deep dive into the fascinating world of the Asterina starfish, a tiny but significant inhabitant of our ocean’s tidal zones. These echinoderms, often no larger than a coin, may go unnoticed by the casual beachgoer. However, they play a crucial role in the marine ecosystem. Let’s embark on an exploration of these small, yet mighty creatures of the sea.

Anatomy and Physiology of Asterina

The Complex Structure of Asterina

Asterina starfish, belonging to the class Asteroidea, exhibit a fascinating anatomy tailored for survival in the intertidal environment. Their bodies are a marvel of biological engineering, with a central disc surrounded by multiple arms, typically five, although some species may have more or fewer. The underside of these arms houses hundreds of tiny tube feet, operated by a unique water vascular system, essential for locomotion, adhesion to rocky surfaces, and feeding.

The Water Vascular System Explained

The water vascular system of the Asterina starfish is a hydraulic system used for movement and feeding. Comprising a network of fluid-filled canals, it culminates in the tube feet, which extend or retract by the force of the fluid within. This system is not only a hallmark of echinoderms but also a marvel of nature’s design, allowing these creatures to adhere to substrates, capture prey, and navigate their often turbulent habitats.

Habitat and Distribution

Preferred Environments of Asterina

Asterina species, such as Asterina gibbosa, are found in various marine environments but exhibit a preference for rocky intertidal zones. These areas, where the sea meets the land, are rich in microhabitats and food sources, ideal for these opportunistic feeders. They have adapted to the ebb and flow of the tides, hiding in crevices or under algae to avoid desiccation during low tides.

Global Reach of Asterina Species

The distribution of Asterina starfish is global, with species occupying both temperate and tropical waters. They demonstrate a remarkable adaptability to varying salinity and temperature conditions, which is a testament to their evolutionary success. From the cold waters of the Northern Hemisphere to the warmer regions of the Southern Hemisphere, these starfish have colonized a wide range of coastal areas, underlining their ecological versatility.

Diet and Feeding Habits

The Omnivorous Nature of Asterina

Asterina starfish are not picky eaters. They are omnivores with a diet that can include algae, detritus, and small invertebrates. Some species have even been observed preying on coral polyps, which has led to their reputation as a pest in reef aquariums. The feeding mechanism involves everting their stomachs out of their mouths to digest food externally before ingesting it, a process that is as efficient as it is unusual.

Impact on the Marine Food Web

Despite their small size, Asterina starfish have a significant impact on the marine food web. They help control algal growth and contribute to the breakdown of organic material, thereby influencing nutrient cycling within their ecosystems. Their predatory habits also play a part in maintaining the delicate balance of marine life in their habitats, making them an integral component of the biodiversity of the tidal zones.

FAQs about the Asterina Starfish

1. What distinguishes the Asterina starfish from other starfish species? The Asterina starfish are typically smaller and have a more flattened shape compared to other starfish. They also possess the ability to reproduce asexually through a process called fission, where an individual can split into two and regenerate missing parts, a feature that is not common in many other starfish species.
2. How do Asterina starfish contribute to their ecosystem? Asterina starfish play a vital role in their ecosystems by controlling algae populations, recycling nutrients, and serving as prey for other marine animals. Their feeding activities help maintain the balance of marine life in the tidal zones, proving their importance in the oceanic food web.
3. Can Asterina starfish be harmful to coral reefs? Yes, some Asterina starfish species can be harmful to coral reefs. For example, species like Asterina burtoni are known to feed on coral polyps, which can lead to significant damage to coral reefs, especially in aquarium settings where their population growth is unchecked.
4. What factors affect the survival of Asterina starfish? Asterina starfish are affected by water temperature, salinity, and the availability of food sources. They are also impacted by ocean acidification and pollution, which can harm their habitats and reproductive capabilities.
5. How do Asterina starfish reproduce? Asterina starfish can reproduce both sexually and asexually. Sexual reproduction involves the release of sperm and eggs into the water, where fertilization occurs. Asexually, some species can regenerate from a single arm.