Mottled Twister

Bellapiscis lesleyae adults can grow to a maximum length of 6 cm, reaching 5-5.5 cm by the end of their first year of life. The body is spindle-shaped, attached to a concave dorsal head. B.lesleyae has three dorsal fins with 18-22 spine rays and 10-15 soft rays. The anal fin is a single fin with 2 spine rays and 17-22 soft rays. The pelvic fins have one spine ray and three soft rays and the pectoral fins have 15-18 soft rays. Bellapiscis lesleyae has mottled colouration. The head and body are whitish to brown and are patterned with dark spots and saddles. The pectoral, dorsal and caudal fins are translucent and the sides of the body display dark, oblique bands with complementing white streaks. B. lesleyae has rays that contain dark brown or black spots. B. lesleyae has an abundance of ctenoid scales which have comb-like edges covering its body. These scales overlap and increase flexibility in body movement compared to other scale types. Sexual dimorphism is not prominent in Bellapiscis lesleyae. However, females of B. lesleyae have a larger body width and depth than males of the same size during spawning. Males also have intense red colouration during courting to attract females. Aside from this, there are no distinct differences between males and females of B. lesleyae. There are several features which differentiate Bellapiscis lelseyae from it sister species, B. medius. B. …

Bellapiscis lesleyae is endemic to New Zealand. The recorded distributions of B. lelseyae ranges from the far north in the Three King Islands, to the south including the Chatham Islands and Stewart Island. Individuals of B. lesleyae are also found on both the east and west coasts of New Zealand as well as south of Fiordland.

Breeding season occurs annually from May to September. Individuals of Bellapiscis lelseyae do not form monogamous mating pairs. Females of B. lesleyae take no role in brood care. Males of B. lesleyae court females by aggressive displays of defence in their territory and shows of colouration. Courting displays occur at the beginning of the breeding season and males will lure one or more females into their territory. Females prefer larger males with inviting displays. B. lesleyae reproduce through external fertilization. Males must provide a substratum for females to deposit eggs. The substratum must provide shelter and protection from disturbance and predation. Once a substratum is selected, the male will release sperm to fertilize deposited eggs. Females of B. lesleyae deposit batches of eggs ranging from hundreds to thousands. Nesting sites can contain eggs laid by more than one female. Observations of habitat use in triplefins including B. lesleyae documented their selection in fine-scale habitats for nesting, such as the sides of rocks or boulders and upside down on the roof of overhangs. B. lesleyae also lay eggs in empty barnacle shells. Overhangs provide less exposure to predatory activity, and rocks and boulders supply gentle currents that can oxygenate eggs without dislodging them. The eggs contain filaments on the outside that can stick to various structures. …