increasing sediment surface area and oxygenating deeper layers of sediment. Burrows of the B. pectinirostris examined in mangrove ecosystems in Pandansari Brebes, Central Java were observed to have diameters of in muddy beach areas and in mangrove areas, identified as belonging to members of the species by tracks left by their fins.Boleophthalmus pectinirostris in Funing Bay, Fujian, China also constructs mud walls around the entrance of their burrows in the winter, creating a shallow walled pool that maintains a relatively consistent temperature, maintains a microphytobenthos (e.g. diatoms) population for food, keeps other fish out, and prevents tides from moving the sediment around and in their burrows. Territorialism Great blue mudskippers are territorial, and males will fight with others of their species over access to burrows and during the breeding season, signalling their aggression by raising their large dorsal fins. The species is also known to compete with the Japanese mud crab (Macrophthalmus japonicus) over food in locations where both species occur. DietBoleophthalmus pectinirostris are herbivores. During low tide, they leave their tunnels to graze on diatoms at the surface. Relationship with humans Culinary useBoleophthalmus pectinirostris is of culinary importance in Japan, and is fished in areas where the species is particularly abundant, such as the Ariake Sea and the Yatsushiro Sea in Saga Prefecture and Kumamoto Prefecture on the island of Kyushu. A style of cooking the fish local to this region involves grilling and basting it whole over charcoal. FishingBoleophthalmus pectinirostris is typically caught by line or by trapping. The line method, referred to as mutsukake, is an unusual method that bears a resemblance to fly fishing, and is carried out at low tide with the use of a long fishing rod, a harpoon-like hook that catches in the fish's skin, and a wooden sled called an oshiita, which is used to travel out onto the tidal flats and to support oneself, as the surface of the flats is too soft to stand on. An alternative means of catching great blue spotted mudskippers is by using long burrow traps made out of hollow bamboo, which are driven into the tidal flat and trap the fish after they enter. Status and conservation As a shoreline species, B. pectinirostris is vulnerable to water pollution and overfishing, and had formerly been in decline from around 1970 due to these factors. However, surveys of the populations in the Ariake and Yatsushiro Sea conducted