Aquaculture, Breeding & Hatchery Mgmt

By definition, one thermochemical calorie ($1\text{ cal}$) is the quantity of thermal energy required to raise the temperature of 1 gram of air-free water by $1^\circ\text{C}$ (specifically from $14.5^\circ\text{C}$ to $15.5^\circ\text{C}$ at standard pressure), which is exactly equal to $4.184\text{ Joules}$ ($1\text{ kcal} = 4184\text{ J}$).

Catla (Catla catla) and Silver carp (Hypophthalmichthys molitrix) are natural surface and upper-column pelagic feeders that actively consume floating extruded pellets at the water surface. In contrast, Mrigal, Common carp, shrimps, and crabs are strict benthic/demersal bottom foragers that require sinking pellets.

Feed binders are substances added to aquaculture feed formulations to improve pellet integrity, mechanical durability, and water stability (preventing disintegration before ingestion). Sodium alginate (a seaweed hydrocolloid) and tapioca starch (gelatinized carbohydrate binder) are outstanding natural feed binders.