Spider (makdsa) any of the members of the order Araneae, class Arachnida having four pairs of legs, and body consisting of a cephalothorax or prosoma, and an unsegmented abdomen or opisthosoma, attached by a narrow stalk called pedicel. The cephalothorax is covered by a shield or carapace, and bears eight or fewer simple eyes. Antennae absent and the sensory functions are in part performed by the walking legs. On the underside of the head (the cephalic part of the cephalothorax) are two pairs of appendages. The anterior pair called chelicerae, is a two-segmented appendage. The apical segment of chelicerae is fang-like and is connected to a venom gland, with which the spider captures and paralyzes its prey, injecting into it venom produced in the poison glands. The spider then liquefies the tissues of the prey with a digestive fluid and sucks this broth into its stomach. The second pair of appendage is known as the pedipalp. In male, it is modified to function as copulatory organ.
Table Number of genera and species of spiders under different families recorded in Bangladesh.
In Bangladesh, more than 412 species of different spiders have been recorded under 134 genera, and 22 families (Table). Araneidae and Salticidae are the most dominant families having 90 and 83 species, respectively. These are followed by Thomisidae (48), Theridiidae (36), Tetragnathidae (35), Clubionidae (22), Lycosidae (19), and Oxyopidae (18).