Morphological description and mitochondrial DNA-based phylogenetic placement of a new species of Callistoctopus Taki, 1964 (Cephalopoda, Octopodidae) from the southeast waters of China

Callistoctopus xiaohongxu sp. nov. A digestive system, female, 83.3 mm ML (OUC-201812050306) B upper beak, lateral view, female, 50.7 mm ML (OUC-201806080302) C lower beak, lateral view, female, 50.7 mm ML (OUC-201806080302) D lower beak, ventral view, female, 50.7 mm ML (OUC-201806080302) E, F scanning electron micrograph of radulae, male, 53.2 mm ML (OUC-201812050302). Abbreviations: a, anus; asg, anterior salivary gland; bm, buccal mass; c, crest; ca, caecum; cr, crop; dg, digestive gland; h, hood; i, intestine; is, ink sac; lw, lateral wing; o, oesophagus; psg, posterior salivary gland; r, rostrum; st, stomach; w, wing. Scale bars: 10 mm (A–D); 200 μm (E, F).