Black porgy is chosen to be the city fish of Keelung, its scientific name is Acanthopagrus schlegelii, inhabit at the depth in 3 - 50 meters, distributes in the west Pacific Ocean, including the coast of Japan, Korean, Taiwan and mainland China. It distributes island wide of Taiwan and Penghu Islands waters.

The black porgy belongs to warm, tropics coastal omnivorous benthic fish. It can be caught year- round, but with specially good taste by the autumn to the next year spring. It can be found in many fish market as high-quality table fish, because of its good flavor. It likes the habitat of inlets with sandy or muddy bottom, sometimes enter the river mouth. It is euryhaline and eurythermal, may be raised in any salinity. It can tolerate the water temperature ranging between l0 ~ 32℃. During the juvenile period all was the male, sex transformation progress until 3-4 year old.