The reproductive biology and early ontogeny of the mouthbrooding Banggai cardinalfish, Pterapogon kauderni (Perciformes, Apogonidae)

Pterapogon kauderni differs from most apogonids in several aspects of its reproductive biology. A breeding pair often allows a secondary male to intervene during mating. Each clutch consists of about 40 eggs 3 mm in diameter, held together by chorionic filaments and is incubated in the buccal pouch of the male for approximately 19 days. P. kauderni is the first apogonid in which direct development is described. Embryos hatch at post-flexion stages measuring about 6 mm SL and remain in the male's oral cavity for another ten days. When released as juveniles they measure 8 mm SL, their large yolksac is almost entirely consumed, and they do not pass through a planktonic interval. After release, juveniles do not return to the male's mouth for refuge, and any association between the male and newly released juveniles ceases. Juveniles reach 30 mm TL after four months and mature in another five to seven months. The embryo and juvenile development is presented.