Gill netting is the most ubiquitous, universally practiced fishing method across marine, estuarine, and inland waters worldwide. Gill nets are passive, highly size-selective, low-cost, fuel-efficient, and easily deployed from small non-motorized canoes to large commercial driftnet vessels.

Gear selectivity characteristics across commercial fishing gears:

• sigmoid (logistic S-shaped) selection curve is characteristic of trawl codends, where retention increases monotonically from 0 to 100% as fish body size exceeds mesh opening.
• Asymptotic curves describe knife-edge selectivity or cumulative asymptotic gear retention.
• Linear curves do not represent physical gear hydrodynamic interactions.
• standard gillnet exhibits a unimodal, symmetrical bell-shaped (normal/Gaussian) selectivity curve. Fish that are too small easily swim through the mesh openings without capture, while fish that are too large cannot penetrate past their opercular girth to become wedged, meaning capture efficiency is maximized strictly within an intermediate, narrow length/girth range.

Classification and regional operation of specialized fishing gears:
Statement (I) is true: A verandah net is a specialized composite barrier trap gear consisting of a vertical blocking barrier net combined with a horizontal floating netting shelf ('verandah'). When jumping fishes (such as grey mullets or milkfish) hit the vertical barrier, they leap into the air and fall onto the horizontal verandah netting where they are captured.
Statement (II) is true: Chinese dip nets (Cheena vala) are giant cantilevered shore-operated lift nets that are an iconic, widely operated artisanal fishing gear throughout the brackish backwaters and estuaries of Kerala (notably around Kochi and Vembanad Lake).