Lop (Thai Valve Fish Trap) — a Cylinder of Bamboo Slats on Hoops, With Funnels at the Mouth and in the Middle, Set in Drainage Channels Against the Current

"At the mouth of the lop, slats are made into a funnel, tied with cord round the mouth with the funnel's tip turned inward; the funnel is cone-shaped. In the middle of the lop another funnel of the same kind is tied inside as a second layer." (Sirindhorn Anthropology Centre, author ทำนุ วรธงไชย (Thamnu Worathongchai), CC BY 4.0)

Whittle bamboo into slats of equal size and make several round frames, called plok, for a lop about 80 cm long and about 30 cm across.

Tie the slats to the hoops at intervals along the length; between the hoops, bind each slat with cord so the gaps are even and the body is strong. The lop is a cylinder with a cut-off mouth, its upper end turned up slightly.

Make a cone-shaped funnel of slats and tie it round the mouth with its tip turned inward; tie a second funnel inside the middle of the lop. Close the back with bamboo strung on cord as a square opening that can be untied to empty out the fish.

Photos of real lop traps from the Nong Bua Khok Folk Museum (Sirindhorn Anthropology Centre, author ทำนุ วรธงไชย (Thamnu Worathongchai), CC BY 4.0).

When the farmers drain water from the paddies through a drainage channel, set the lop with its back facing upstream so its mouth catches fish swimming against the current. Cover the top with grass and weigh it down with earth so the lop is not carried away. It traps by day and by night; check it from time to time.

The name may come from the verb "lop", to lie in hiding, because the lop lies still waiting for water animals. A small lop is also used to trap frogs in paddies that are drying, baited with minnows, shrimp or fry put inside. Some have a square door at the mouth, and a "nga wai" funnel tied with a cord that can be pulled tight or let slack. Take care with spiny fish when emptying it. Source: Sirindhorn Anthropology Centre, Traditional Objects of Everyday Use database, "ลอบ", author ทำนุ วรธงไชย (Thamnu Worathongchai), Nong Bua Khok Folk Museum, Buriram (CC BY 4.0 licence). **Limits** The source does not give the number of slats or hoops, or the size of the funnels.