Swimming against the tide: Scientists unveil the unique diet of garden eels

The Red Sea crown-of-thorns starfish is an endemic species

LMU researchers have identified coral-eating crown-of-thorns starfish in the Red Sea as a distinct species found only here.

Tropical coral reefs are among the most endangered ecosystems on earth. In addition to climate change, coral-eating crown-of-thorns starfish (acantaster spp.) represents one of the greatest threats in parts of the Indo-Pacific region. The animals, which can be up to 40 cm long, feed mainly on the polyps of fast-growing hard corals. Mass outbreaks are not uncommon, with starfish spreading rapidly and many thousands of individuals devastating large areas of coral reef. Such mass outbreaks have become increasingly common in recent decades, partly because the starfish’s natural enemies have been decimated by overfishing.

Crown-of-thorns starfish are widespread in the Indo-Pacific. They get their name from the large venomous spikes that protrude from their arms. Different species have been described in the past due to regional morphological differences. However, relations between them remained somewhat hazy. “For a long time it was thought that the first species of the described genus, acanthaster planci, distributed from the Red Sea and Indian Ocean across the entire Pacific,” says Gert Wörheide, Professor of Paleontology and Geobiology at LMU. However, this was shown by DNA barcoding data from a doctoral thesis supervised by Wörheide more than 10 years ago A.planci can be divided into four widely divergent genetic lineages that are believed to represent distinct species. A team led by Wörheide and Gerhard Haszprunar, Professor of Systematic Zoology at the LMU, has now used morphological studies and genetic analyzes to prove that the crown-of-thorns starfish native to the Red Sea form an independent species, which is given the name Acanthaster benzei. “This once again underlines the importance of the Red Sea as an ecosystem with a unique fauna and numerous endemic species,” emphasizes Wörheide. The new species name honors John Benzie, a professor at University College Cork who pioneered his pioneering genetic studies of crown-of-thorns starfish in the 1990s and his extensive collection.

Fewer arms, thinner spikes

With A. benzeiFor the first time in several decades, scientists succeeded in describing a new species of crown-of-thorns starfish. “Although anecdotal features have already been observed in Red Sea crown-of-thorns starfish, such as a tendency to be more nocturnal and a presumed lower toxicity of the spines, we did not yet know that it is actually a distinct species,” says Wörheide The research confirmed clear differences between HAS. Benzei and the other types of “A.planci” species complex. In addition to characteristic sequences in the mitochondrial DNA, this also included morphological features such as a smaller number of arms and thinner, differently shaped spines.

“Now that we know it’s a distinct species, we can turn our attention to the biology, ecology and toxicology HAS. Benzei and the other acantaster species,” says Wörheide. Scientists had also observed a reduced tendency for mass outbursts in crown-of-thorns starfish in the Red Sea in the past. “Such outbreaks are mainly known from acantaster see solaris in the western Pacific and regularly cause major damage to the Great Barrier Reef, while the phenomenon appears to be less severe in the Red Sea – whether species-specific features play a role could be the subject of future investigations,” says Wörheide. Most of the data available so far on the biology and ecology of crown-of-thorns starfish are from acantaster see solaris from the western Pacific. “By clearly distinguishing the different species of coral-eating crown-of-thorns starfish, we can more closely study the dynamics of mass eruptions, one of the many stressors affecting tropical reefs. Ultimately, this is a step in the right direction towards better management of reef ecosystems.”

story source:

Materials provided by Ludwig-Maximilians-University Munich. Note: Content can be edited for style and length.

#Red #Sea #crownofthorns #starfish #endemic #species

Leave a Comment

Your email address will not be published. Required fields are marked *