Sarcophagidae; Sea earthworm

A general term for the polychaete sarcophagidae in annelids. Also known as sea earthworm. It is a large worm with a cylindrical body, a small head, a trilobal shape and an upturned sac. The trunk can be divided into 2 ~ 3 body areas. There are no gills in the chest and gills in the abdomen.

Sandfly (5 photos)

A slender, segmented tail region. Shuang Ye's wart foot. Sand flies are the dominant species at the bottom of mudflats in intertidal zone and estuary, and they lurk in L-shaped or U-shaped caves. Swallow a lot of sediment and digest organic matter and small animals. Due to continuous swallowing, the sediment above the worm's head sinks, forming a funnel-shaped opening. There are 4 genera and nearly 30 species in the world. In China's Yellow Sea and Bohai Sea, August-September is the peak of breeding, and spherical or elliptical colloidal egg bags are attached to the beach surface with sunken heads.

Annelida is the general name of all marine worms of polychaeta and Sarcophaga. They tend to be bigger. Deep drilling in sandy seabed or intertidal zone. Fishermen use it as bait. The adults of sand flies (such as sand flies [[〔A. marina〕]] along the coast of Europe are about 23 cm (9 inches) long. A. cristata along the coast of North America is 7.5 ~ 30 cm (3 ~ 12 inch) long. Sand flies are segmented, with a crimson head and a wide and light body segment behind the head. Gradually tapering, yellow-red. There are bristles in the middle of the body, about 12 pairs of pinnate gills. Feed on organic debris and swallow it with sand. At low tide, you can see the coiled feces discharged by it at the mouth of the cave. The drilling depth can reach 60 cm (2 feet). Androgyny. Homologous fertilization