Due to the difficulties in determining precisely when a small species is sexually mature (i.e. an adult and fully grown), there are two, possibly three, contenders for the smallest spieces of shark. The most likely record holder is the dwarf lantern shark (Etmopterus perryi), males of which measure a total length of 16-17.5 cm (6.3-6.8 in) (with one confirmed male adult specimen collected measuring 19 cm or 7.4 in long), and mature females of which are typcially 19-20 cm (7.4-7.8 in). Prior to the discovery of the dwarf lantern shark, the record holder was the spined pygmy shark Squaliolus laticaudus, males of which measure 15 cm (6 in), females 17-20 cm (6.7-7.8 in). A third rival species, the pygmy ribbontail catshark Eridacnis radcliffei, has males measuring 18-19 cm (7-7.4 in) and females possibly mature at 15-16 cm (6-6.3 in).