The article below is extracted and adapted from National Geographic News.

At least 20 new species of sharks and rays have been discovered in the waters off Indonesia, scientists announced. The finds are the result of a five-year survey—mostly done at local fish markets—to catalog what types of sea creatures are living, and being caught, in a region known for its rich aquatic diversity.

This sleek, spade-shaped Hortle’s whipray (see Figure 1), for example, is the newest of 17 whipray species known to live in the muddy shallows along Indonesia’s shores. The announcement also comes just six months after another expedition discovered more than 50 colorful and often strange new species among Indonesia’s coral reefs.

“Indonesia has the most diverse shark and ray fauna and the largest shark and ray fishery in the world,” said biologist William White in a statement from Australia’s Commonwealth Scientific and Industrial Research Organization (CSIRO), which led the new survey. “Before this survey, however, there were vast gaps in our knowledge of sharks and rays in this region.”

Distinguished by its trout-like colors and leopard-like spots, this Bali catshark (see Figure 2) is one of the 20 unusual new species discovered recently in Indonesia. From 2001 to 2006, researchers from five Australian and Indonesian institutions sampled more than 130 shark and ray species on 22 trips across the roughly 17,000 islands of Indonesia.

The project was the first in-depth survey of the country’s sharks and rays to be done in nearly 150 years. The last such study was done by Dutch biologist Pieter Bleeker, who cataloged more than 1,100 fish species in the region between 1842 and 1860. Much of the scientist’s research was discounted at the time, however, because his colleagues refused to believe that such a diversity of sea life was possible. In a long-delayed vindication of his work, biologists who took part in the new survey announced that they “agreed with Bleeker’s findings.”

With the body of a shark and the head of a ray, this Jimbaran shovelnose ray (see Figure 3) is living proof of the ancient relationship shared by the two fish families. Sharks and rays are both elsmobranchs, fish that have skeletons made of cartilage instead of bone. The Jimbaran shovelnose was discovered recently in Indonesia as part of a five-year survey of the country’s shark and ray species.

This species of shark recently discovered in Indonesia, called a whitefin smooth hound (see Figure 4), closely resembles similar sharks found as far away as Mexico. Its discovery may provide important insights into the effects of fishing on shark populations, as smooth hounds are commonly caught as food.

The growing popularity of shark-fin soup in regions from China to California has caused an increased demand for shark meat, which scientists say calls for close attention to the trade’s effects on shark numbers. “Good taxonomic information is critical to managing shark and ray species, which reproduce relatively slowly and are extremely vulnerable to overfishing,” said CSIRO biologist William White. “It provides the foundation for estimating population sizes, assessing the effects of fishing, and developing plans for fisheries management and conservation.”