That, Steve, is an aptly named yellowbelly threadfin bream (Nemipterus -bathybius). Threadfin bream (also known as whiptail bream), in the family Nemipteridae, are a diverse group of over 60 species of small, perchlike fishes found throughout the -tropical Indo-Pacific. Yellowbelly threadfin bream are commonly found over sandy or muddy bottoms at depths of 100 to 1,000 feet throughout the western Pacific, from Japan south to Indonesia and northwestern Australia. Juvenile N. bathybius up to 4 inches long feed on planktonic crustaceans (copepods, ostracods and amphipods), while adults grow to around 8 inches long and feed mainly on shrimp, crabs, smaller fish and squid. This species is what is called a rudimentary hermaphrodite, which means the males have functional testes but also a rudimentary ovary. For such a small species they’re relatively long-lived, with fish from southern Japan aged to a maximum of 8 years for males and 10 years for females. This bream’s reddish colors look bright at the surface in -daylight, but at depths below 100 feet, where red light wavelengths are attenuated, the color becomes far less visible and could even be a form of -camouflage.