Eoperipatus totoro

Eoperipatus totoro is a species of velvet worm of the family Peripatidae. This species is notable as the first velvet worm from Vietnam to be formally described. As of 2023, E. totoro remains the only species of velvet worm from Vietnam to be described.

Discovery
Pavel V. Kvartalnov from the Lomonosov Moscow State University found the first specimen of E. totoro while looking under stones in the Crocodile Lakes area of Cát Tiên National Park in Vietnam with Eduard A. Galoyan and Igor V. Palko from the Vietnam-Russia Tropical Centre in November 2007. Vietnamese researchers Thai Dran Bai and Nguyen Duc Anh first described this species in 2010, but a team led by Ivo de Sena Oliveira from the University of Leipzig published the first formal species description in 2013, including data from scanning electron microscopy and molecular analysis (mitochondrial COI and 12S rRNA sequences). This team described this species based on two male specimens, including a holotype collected by Peter Geissler of the Alexander Koenig Research Museum in 2009, and five females, including two paratypes collected by Kvartalnov in 2008. Although this species remains the only velvet worm described from Vietnam, a report of another velvet worm found in another part of Vietnam indicates that at least one other species in that country remains undescribed.

Etymology
The generic name Eoperipatus is derived from an Ancient Greek combining form of Ἠώς (ēṓs), meaning "dawn", and peripatos, meaning "walking about". The specific name totoro was suggested by Kvartalnov, Galoyan, and Palko, after the titular character in the Japanese animated film My Neighbor Totoro who uses a vehicle (the Catbus) that resembles a velvet worm. Kvartanov and his colleagues watched this film on the evening of their discovery of the first specimen, which reminded them of the Catbus.

Description
This species is dark brown on the dorsal surface and brownish pink on the ventral surface. Females have 24 pairs of legs; males have 23 pairs of legs. The ventral surface of the legs are pink, and the first and last leg pairs are reduced in size. This species can reach 65 mm (2.6 in.) in length. Diagnostic features include distinct types of scales on the ventral side of the body, the inner structure of the circular pits on the male genital pad, and the position and size of the anal gland pads in males.

Before 2013, only three valid species of Eoperipatus were recognised in Southeast Asia. E. totoro differs from these other species in the spherical shape of the apical pieces on its dorsal primary papillae and the position of its nephridial tubercle in the fourth and fifth leg pairs (in between the third and fourth spinous pads). Furthermore, E. totoro features repeated bright spots along the ventral midline between its legs.

These velvet worms have permeable skin that readily dries out, so they spend most of their lives inside moist soil, in rotting logs, or under rocks. They are found mainly during the rainy season, which runs from November to June in Vietnam. Like other velvet worms, this species can spit out jets of sticky adhesive fluid from two dorsal appendages to capture small prey; this "glue" is a mixture of proteins in which the prey becomes entangled.