Panulirus ornatus
editPanulirus ornatus, commonly known as the tropical rock lobster,[1] ornate rock lobster, ornate spiny lobster or ornate tropical rock lobster, is a large edible spiny lobster with 11 larval stages that has been successfully bred in captivity.
P. ornatus has a wide geographical range in the Indo-Pacific, from Torres Strait off of Australia's northern coast to various regions around Indonesia. These lobsters can be found at shallow depths, typically no deeper than 50 m.[2] In most areas, the lobster is netted or speared. In Northeast Australia, where commercial fisheries have existed since 1966, the harvesting of the species is regulated by the Great Barrier Reef Marine Park Authority.[3] The species now also occurs in the Mediterranean, having invaded as a Lessepsian migrant through the Suez Canal.[4]
The species is responsible for supporting a number of fisheries in Vietnam, Papua New Guinea, the Torres Strait in Australia, and other Indo-Pacific regions.[5] With such stress on a single species for commercial purposes, countries like Australia and Indonesia have started successful aquaculture practices.
Description
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The ornate rock lobster is a large specimen with a blue-green carapace. They are characterized by their large frontal horns, as well as distinct patterning with stripes and spots of various colors throughout their bodies. Their legs have intricate stripe patterns, making them appear almost spider-like.[6]
Diet
editThe P. ornatus diet consists of a variety of invertebrates, including bivalves, gastropods and even other small crustaceans. Carotenoids are crucial for the diet of P. Ornatus, providing energy and antioxidants in addition to aiding in reproductive success, post-larval development, and even stress resistance. Within aquaculture facilities, farmers rely on special feeds made up of Carotenoids, specifically astaxanthin. Many feeds also rely on nutrients from blue and green-lipped mussels, but experiments have shown that the carotenoid level offered from these feeds alone is not sufficient for the lobsters’ development.[7]
Breeding and migration
editPanulirus ornatus migrates annually from the Torres Strait to Yule Island in the Gulf of Papua in order to breed.[5][8] Migration begins in mid to late August,[9] during which ovary development, mating, and initial oviposition occur. Larval release occurs when the Panulirus ornatus population ends migration and arrives on the reefs of the eastern seaboard of the Gulf of Papua.
The breeding season for Panulirus ornatus begins in November and March or April.[5][8] After migration to the Gulf of Papua, the sexes segregate by water depth. Females, waiting for the eggs to hatch, remain in deep waters while males settle in shallower waters. Female Panulirus ornatus produce up to three broods with a reduction in size of each subsequent brood.[5]
Most breeding adults are three years old. Mating males tend to be larger than females, with carapace lengths ranging from 100-150 mm, and that of females ranging from 90-120 mm. After breeding, there is high mortality in breeding adults.[8]
There is no return migration of breeding adults. Reproductive migration across the Gulf of Papua occurs in order to disperse larvae in oceanic currents that favor their distribution near the Torres Strait. Dispersed throughout the eastern coast of Australia, Panulirus ornatus larvae must migrate as juveniles to the adult habitat in the northern Torres Strait. From there, they remain in specific reef complexes for 1-2 years until they are of breeding age and undertake the annual mass migration to breed.[9]
Aquaculture/Farming
editThese lobsters are great candidates for aquafarming because of their ability to grow very quickly. It takes only 18 months for P. ornatus to grow up to 1 kg in the wild.[7] Those that exceed this 1 kg baseline are most commercially desirable and profitable.[10] As a result, many Southeast Asian countries, including Vietnam and the Philippines, have tested feeding pellets designed to promote larger growth.
Seed Lobsters (Pueruli)
editSelling wild-caught, out-grown rock lobster originated in countries like Vietnam and China. In the early 2000s, it was discovered that the waters surrounding Indonesia hosted the largest P. ornatus communities ever seen and the potential for the world’s largest lobster aquaculture industry. P. ornatus is now the most valuable resource in Indonesian fisheries.[10]
During the puerulus stage (the transition between phyllosoma larva and juvenile lobster), P. Ornatus are sometimes referred to as ‘seed lobsters.’ These seed lobsters, or pueruli, are much more abundant than juveniles, so it is extremely efficient to gather members of this group. Fishers dive down to artificial habitats created specifically for pueruli settlement and periodically extract them. These specimens are then moved to grow-out sectors to mature. This is a mutually beneficial practice, as humans are able to export (and eat) large sums of P. ornatus, and meanwhile this species is subjected to much lower mortality rates in the process. In nature, pueruli mortality rates are about 99%, whereas in capture and on-grown practices, the mortality rate is lowered to under 25%. Hence, aquaculture practices are providing ways of increased lobster production and enhancing natural populations.[10]
In 2015, a law was put into place ending this practice of seed fishing, a practice had been provided livelihoods to thousands of Indonesian households for years. The law required all caught lobsters to weigh at least 200 g. Later, in 2016, a new policy was announced that prohibited grow-out opportunities for lobsters. Seed fishing continued in secret, despite the risk of major penalty and arrest. In 2019, it was estimated that there were more puerulus fishers active than there had been before the new laws were implemented.[10]
- ^ "Tropical Rock Lobsters". Australian Institute of Marine Science. Retrieved March 31, 2021.
{{cite web}}: CS1 maint: url-status (link) - ^ Musbir, Musbir (28 February 2018). "Egg quantity of wild breeders of spiny lobster (Panulirus ornatus) caught from southern coastal waters of Bulukumba, South Sulawesi, Indonesia" (PDF). Aquaculture, Aquarium, Conservation & Legislation - International Journal of the Bioflux Society. 11: 295–300.
- ^ "Commercial fishing and zoning". www.gbrmpa.gov.au. Retrieved 2021-03-31.
- ^ Rodríguez, Gilberto; Suárez, Héctor (2001–2006). "Anthropogenic dispersal of decapod crustaceans in aquatic environments". Interciencia. 26 (7): 282–288. ISSN 0378-1844.
{{cite journal}}: CS1 maint: date format (link) - ^ a b c d MacFarlane, J. W. (1986). "Reproduction of the Ornate Rock Lobster, Panulirus ornatus (Fabricius), in Papua New Guinea". Australian Journal of Marine and Freshwater Research. 37: 55–65.
- ^ Ranjan, Ritesh (2017). Prioritized Species for Mariculture in India. India: Central Marine Fisheries Research Institute. pp. 221–225. ISBN 978-93-82263-14-2.
- ^ a b Barclay, M. C.; Irvin, S. J.; Williams, K. C.; Smith, D. M. (2006). "Comparison of diets for the tropical spiny lobster Panulirus ornatus: astaxanthin-supplemented feeds and mussel flesh". Aquaculture Nutrition. 12 (2): 117–125. doi:10.1111/j.1365-2095.2006.00390.x. ISSN 1365-2095.
- ^ a b c Dennis, D. M.; Skewes, T. D.; Pitcher, C. R. (1997). "Habitat use and growth of juvenile ornate rock lobsters, Panulirus ornatus (Fabricius, 1798), in Torres Strait, Australia". Marine and Freshwater Research. 48 (8): 663–670. doi:10.1071/mf97184. ISSN 1448-6059.
- ^ a b Moore, R; MacFarlane, Jw (1984). "Migration of the Ornate Rock Lobster, Panulirus ornatus (Fabricius), in Papua New Guinea". Marine and Freshwater Research. 35 (2): 197. doi:10.1071/MF9840197. ISSN 1323-1650.
- ^ a b c d Priyambodo, Bayu; Jones, Clive M.; Sammut, Jesmond (2020-11-15). "Assessment of the lobster puerulus (Panulirus homarus and Panulirus ornatus, Decapoda: Palinuridae) resource of Indonesia and its potential for sustainable harvest for aquaculture". Aquaculture. 528: 735563. doi:10.1016/j.aquaculture.2020.735563. ISSN 0044-8486.