Every child who has fished from a New Zealand wharf has caught a spotty. Small, inquisitive and extraordinarily willing to take a bait, the paketi is the fish that introduces most New Zealanders to the concept of fishing. And then to the concept of unwanted bycatch. It is too small to keep. Too persistent to ignore. It will take a hook baited for snapper with the confidence of a fish that has never considered the possibility of consequences. The optimism is touching. The outcome is predictable. Notolabrus celidotus is the most common wrasse in New Zealand. It is endemic throughout the country from Northland to Stewart Island. Found on every rocky reef with sufficient structure and algal cover. Females are olive-brown with pale spots and a white belly. This colour scheme is responsible for the common name. Males are a different proposition entirely. Vivid orange-green or turquoise. Iridescent markings define their presence. Far more conspicuous on the reef. The two sexes look different enough that early naturalists classified them as separate species. The error was understandable. The dimorphism is striking. That is because they were the same individual at different stages. Spotties are protogynous hermaphrodites. They begin life as female. If large and dominant enough, they transition to male at around 13 to 19 centimetres and three to four years of age. The transition involves a complete remodel of the colour pattern. The hormonal system changes. The behaviour shifts. Terminal-phase males establish territories. They maintain harems of roughly twenty females. They aggressively defend both from rival males. Initial-phase males use a different tactic. Smaller and female-coloured, they infiltrate spawning events. They mimic females convincingly enough to pass inspection. Both strategies produce offspring. The biology of sex change in the spotty is well documented. The species has become a standard laboratory model for studying sequential hermaphroditism in vertebrates. The cooperation is notable. Diet is benthic and opportunistic. Those strong teeth are designed for prising invertebrates from rock surfaces and kelp holdfasts. Not for chasing prey in open water. Amphipods, small crabs, molluscs and worms are the primary items. Picked off reef surfaces with the deliberate, head-down focus of a bird working a lawn. The method is precise. The energy cost is low. The reward is consistent. The spotty is not a food fish. It is too small. Those who have eaten one report results that do not encourage repetition. Its value is ecological. A common and abundant reef invertebrate predator. And scientific. A model organism that has proved considerably more cooperative in captivity than most reef fish manage to be. The utility is specific. The culinary appeal is nil. The educational value is high. It remains the gateway species. The first catch. The lesson learned. It carries on.