Taiwan’s Coral Fish - Beauty is not a Curse

Taiwan has some of the world's richest marine resources, and a tremendous diversity of marine life that call it home. It's impossible to imagine, but the waters around Taiwan host about one tenth of the world’s marine species, which is 400 times the average number for other coastal countries. Coral reefs, which make up less than 0.3% of the world’s oceans, can be found not only at the northern and southern tips of Taiwan, but also around Taiwan’s offshore islands such as Green Island, Penghu, and Lanyu. Located at the edge of the world’s largest continental shelf, just north of the bio-diverse East Indies, Taiwan can claim such exceptional marine resources. The fact that Taiwan encompasses a wide range of different marine habitats, including sand shoals in the west and several-thousands-deep coasts in the east, also contribute to its remarkable bio-diversity.

Among all marine habitats, coral reef systems are the richest in marine life. There are up to 1,500 kinds of coral fishes, accounting for one third of the world’s overall coral fish species and more than 60% of Taiwan’s total fish species. Thanks to the favorable latitude and ocean currents (especially the Kuroshiro Current which travels up from the equator), many tropical creatures are carried as eggs, larvae, or even adults to Taiwan's southern coast.  Places like Kenting, Lanyu, and Hsiao Liuchiu Island are rich in an ever-restored population of marine animals. The water temperature of northern Taiwan and northern Penghu, affected by cold currents traveling down from Fujian and Zhejiang in mainland China, is five to six degrees lower than that of southern Taiwan. Such colder waters are ideal for many sub-tropical species, bringing an entirely different range of life to Taiwan’s northern shores. Despite being a small island that boasts a mere 364 kilometers of coastline, Taiwan has two completely different marine landscapes and coral reef systems.
The most well-known inhabitants of colorful coral reefs are the vibrant tropical fish. Coral fish species come in a wide variety of sizes and colors. Best known are the bright and playful wrasses, the long, snake-like conger eels, and the sharp-beaked parrot fish. There are gobies which are so tiny that they can only be seen clearly under a magnifier; there are also disc-thin angelfish, vertically compressed flatfish, and Tetraodontidae, which are shaped like spheres. When it comes to the color, there are bright-yellow oval-spot butterfly fish, blue striped emperor angelfish, and fish which change their colors or even sexes throughout their lifecycles. Taiwan’s coral fish also feed on a wide array of foods: some are herbivorous, some are carnivorous, while still others are omnivorous. Some feed on plankton, while a few actually feed on parasites picked from the bodies of other fish. In addition to living in cavities or nooks of coral reefs, some of these fishes can rest under the sand. Still some others, such as coral crouchers and gobies, can only live in very specific places, such as at coral branches or underneath sea whips/sea sponges respectively. There are also species which have developed unique symbiotic relationships, such as the well-known clown fish who make there homes inside friendly sea anemones, and members of the Eleotridae family who live with pistol shrimp, warning them of danger in exchange for a safe place to lay their eggs.
However, Taiwan’s wonderful marine habitats are gradually disappearing, becoming a victim of people’s ignorance, negligence, and greed. Garbage dumped along coastlines, overexploited shores, and untreated sewage water all contribute to rising silt levels that cover coral reefs and suffocate the living coral’s vulnerable polyps. This is without doubt the most pressing threat to the survival of coral reefs. Unscrupulous fish vendors illegally catch large numbers of colorful fish to sell as aquarium pets; little do they realize that it is an endless torture for coral fish to be kept in manmade environment. The unique and exotic appearance of coral fishes also draw interest of many so-called gourmands. Nevertheless, most coral fish species are small with very little meat, and are likely to contain ciguatera poisoning; therefore, they have little edible value. The situations outlined above have made the number of the most commonly seen coral fish species in Taiwan fall from hundreds to only several dozens. These valuable marine resources are best shared with humanity by means of bio-tourism. Directly consuming them will not only reduce these valuable resources, but also destroy the fragile ecological balance of the area. Sustainable use does not suggest finding ways to consume marine resources endlessly; it means to figure out ways to co-exist harmoniously with nature. Through these collections of coral fish species, it is hoped that more people will recognize the beauty of coral fishes and the ways to further protect them.
Orangespot Surgeonfish (Acanthurus olivaceus)
Also known as Orange Shoulder Tang for the blue-bordered orange band near its eye, Orangespot Surgeonfish inhabits coral reefs, feeds on algae, and is diurnal. It is sometimes called the “surgeonfish” because of the two inverse scalpel-like thorns on its tail. When it senses danger, the thorns will rapidly fan out to scare off or attack its enemies. Juveniles stay at shallow bays and usually live alone or in small groups. Adults live in deeper areas and are more likely move in groups.
Above Picture: Orangespot Surgeonfish
The fish commonly known as clown fish belongs to the subfamily Amphiprioninae of the Pomacentridae family. This subfamily includes two genera: Amphiprion and Premna. While there are twenty-seven species in the genus Amphiprion, only one is listed under the genus Premna. Currently Taiwan is home to five species of clown fish, all members of the genus Amphiprion. They are the Ocellaris Clownfish (Amphiprion ocellaris), the Saddleback Clownfish (Amphiprion polymnus), the Pink Skunk Clownfish (Amphiprion perideraion), the Red Clownfish (Amphiprion frenatus), and the Yellowtail Clownfish (Amphiprion clarkia).
Clown fish have a distinctive feature: their sex changes. Whatever their original sexes are, when clown fish reach a certain age, the stronger individuals begin to dominate other members of the species through chasing and biting them. In reaction to the repressive action, the smaller and weaker ones either transform into males or lose their gonads, while the stronger ones become females. This explains why a larger clown fish is usually accompanied by several smaller ones at a single anemone.
All clown fish are born males and contain immature ovarian tissue. When a female dies, the superior male will change into a female with full sexual function within two weeks. Once becoming a female, a clown fish can never change back to a male. In the meantime, the male second in order will become the reproductively capable male. Such particular social patterns and sex-changing mechanism are significant to the continuance of this species since clown fish remain in the same anemones and seldom come into contact with members of another community. With this sex-changing behavior, there will always be one breeding pair in a group to ensure the continuance of its generations. Accordingly, there is always a hierarchical system to prepare each member of a group for replacement.
Above Picture: Yellowtail Clownfish
Black Back ButterflyfishChaetodon melannotus
The Black Back Butterflyfish inhabits coral reef areas and is diurnal. It feeds on coral polyps. A juvenile has a fake eye spot at its tail to misdirect an enemy’s attack so as to increase the chance of escaping. The fake eye spot will fade gradually as it becomes more capable of defending itself as its age advances. Adults usually live in pairs or in schools.
Above Picture: Black Back Butterflyfish
Vagabond Butterflyfish (Chaetodon vagabundus)
The Vagabond Butterflyfish has chevron-like stripes. It is diurnal, inhabits coral reefs, and feeds on coral polyps, algae, and benthic animals. Vagabond Butterflyfish usually live in pairs and are strongly territorial. The black band passing through the eyes can misdirect potential predators, preventing the eye from being attacked directly.
Above Picture: Vagabond Butterflyfish