No.44 Mantis shrimp

The killer whale is a crustacean belonging to the family Ornithopodiidae, and is widely distributed on shallow seabeds in tropical and temperate zones. They are widely found in the seas around Japan, and in Osaka Bay, they live alone, digging burrows in the muddy bottom at depths of 10 to 20 meters. They are generally 10 to 20 cm in length, and are characterized by their long, slender bodies and distinctive nipped-in appearance at each node.
The most distinctive feature of killer whales is their forelegs, which are called “catapods,” and they are classified into ‘spear’ and “smasher” types, depending on the species. The individual scanned in this study is a spear type, which quickly thrusts out its front legs with sharp spines to pierce and catch soft prey such as cockles and small fish. Its movements are extremely fast, allowing it to accurately capture prey even in murky or dark water.

This sample was requested by NHK Enterprises, Inc. and CT scans were conducted as a project for NHK E-television's “Gyogyotto Sakana★Star”.
Gyogyotto Sakana★Star" program HP: https://www.nhk.jp/p/ts/P58QMGP4K1/

CT scans revealed complex joint and muscle structures at the base of the catch legs, showing the mechanics that allow the killer whale to attack at high speed. The exoskeleton was thin but strong, and also captured the segmented abdominal structure, the digestive tract that runs along the trunk, and the gill structure at the base of the swimming legs.