Today's guest blogger, marine biologist Dr. J.P. Hobbs, has been studying Christmas Island underwater for over 10 years and has a particular interest in marine hybrids.
'Christmas Island has more hybrid fish than anywhere else in the world, making it a marine hybridization zone of international significance!'
Christmas Island is surrounded by a narrow fringing reef which supports bountiful marine life, including 88 coral species and more than 650 species of fish. The island is located on the edge of the Java Trench, the deepest point in the Indian Ocean, creating spectacular steep drop-offs just beyond the fringing reefs.
Christmas Island’s fish community is distinctive because the island is a meeting place for Indian and Pacific Ocean fish species – it’s one of the few locations in the world where Indian and Pacific Ocean fish swim side by side. Some of these species interbreed to produce hybrids. Christmas Island has more hybrid fish than anywhere else in the world, making it a marine hybridization zone of international significance.
At least 11 different hybrids have been recorded at Christmas Island. These hybrids are often a result of interbreeding between Indian and Pacific Ocean species. Usually one of the parent species is rare and unable to find a partner, forcing it to mate with the next closest species. On Christmas Island, species of surgeonfish, butterflyfish, angelfish, triggerfish, wrasse and toadfish have been know to produce hybrids. The hybrids are identified by their unique colour patterns, which are a mixture of the two parent species.For example, the Lemon Peel and Eibl's Angelfish come together to create the beautiful hybrid pictured above. Hybrids can be seen in the same locations as the parent species and often in the same social groups. So keep your eye out for them the next time you are out snorkelling or diving on Christmas Island.