Panulirus ornatus, also known as tropical rock lobster, ornate rock lobster, ornate spiny lobster, or ornate tropical rock lobster, is a large and delicious spiny lobster that has 11 larval stages and can be raised in captivity.
Panulirus ornatus has a vast geographical distribution in the Indo-Pacific, from the Red Sea to Japan and Fiji. It typically inhabits shallow waters, no deeper than 50 meters. In many parts of its range, it is caught using nets or spears, while in Northeast Australia, there is a regulated commercial fishery established in 1966. The species has also spread to the Mediterranean through the Suez Canal as a Lessepsian migrant.
The diet of P. ornatus includes various invertebrates, such as bivalves, gastropods, and small crustaceans. They need carotenoids for energy and various other benefits, like reproductive success, post-larval development, antioxidants, and stress resistance. In aquaculture facilities, many lobster species are fed crustacean feeds for breeding. These feeds contain high levels of carotenoids, specifically astaxanthin, and also provide nutrients from blue and green-lipped mussels. However, research has shown that these feeds alone do not provide enough carotenoids for the proper development of lobsters.
The Panulirus ornatus species migrate annually from the Torres Strait to Yule Island in the Gulf of Papua for breeding purposes. This migration starts in August and involves ovary development, mating, and the start of egg-laying. The migration ends when the population reaches the eastern seaboard reefs of the Gulf of Papua, where the larvae are released.
The breeding season for Panulirus ornatus is from November to April. After they migrate to the Gulf of Papua, the males and females separate based on water depth, with males in shallower water and females in deeper water until the eggs have hatched. Female Panulirus ornatus can have up to three broods, each smaller than the previous one.
The majority of breeding adults are three years old. During mating, males are generally larger than females, with a carapace length of 100-150 mm for males and 90-120 mm for females. After breeding, a high rate of mortality is observed among breeding adults.
Breeding adults do not migrate back. The reproductive migration across the Gulf of Papua helps disperse larvae via ocean currents that aid in their distribution near the Torres Strait. The larvae of Panulirus ornatus, dispersed along the eastern coast of Australia, must migrate as juveniles to the adult habitat in the northern Torres Strait. Once there, they stay in a specific reef complex for 1-2 years until they reach breeding age and embark on the yearly mass migration for breeding.
