User:K43133N/Squaretail coral grouper

Lead Section

Squaretail coral groupers, Plectropomus areolatus, also known as spotted coral trout or the squaretail coral trout, are fast growing, short lived, and early maturing epinephelus (K. L. Rhodes et al). They are classified as vulnerable, as their populations are decreasing (Squaretailed Coral Grouper | SCRFA).

Anatomy And Morphology

Squaretail Coral Groupers grow to a max length of 80 cm, with the female fish usually larger in length. At first maturity, they are around 36.65 cm long and 771.2 grams (Khasanah et al.). They have 7-8 dorsal spines. They have 1-4 canines on the upper jaw. They are a whitish gray color with dark spots (Ruppell) and a greenish-gray or red to brown color (https://www.fao.org/3/t0540e/t0540e40.pdf).

Distribution and Habitat

Squaretail coral groupers live in shallow lagoonal and seaward coral-rich areas, especially in channels at the reef front (K. L. Rhodes et al)(Squaretailed Coral Grouper | SCRFA) (IUCN redlist). They are widely distributed in tropical coral regions, living in the Indian Ocean and the Pacific from the Philippines to Japan to Australia, also occurring on the Red sea and Maldives. (Squaretailed Coral Grouper | SCRFA). They typically live in 1-70 m depth and in the Marine Nertic, at around 660 ft (IUCN redlist). Squaretail Coral Groupers have small home ranges and many stay close to their aggregation site (Squaretailed Coral Grouper | SCRFA).

The squaretail coral grouper often co-aggregates with camouflage and brown-marbled groupers (IUCN redlist).

Behavior (Reproduction)

(Kevin L. Rhodes et al.)

P. areolatus has an early maturity at around 2.8 years and a relatively brief lifespan at around 10 years. The spawning seasons is 2-3 months, respectively, which falls entirely during January to April. While some regional similarities exist, temperature profiles cannot be used reliably as an indicator of spawning in these species.The temperature profiles during reproductive periods vary.

The spawning times are during new and full moons, which may suggest a linkage to associated high tidal variation and flow to enhance dispersal or retention. Thus, similar to temperature, specific lunar periodicity lacks dependability as an indicator of spawning times and demonstrates the variability within the species for reproduction relative to lunar periodicity (Squaretailed Coral Grouper | SCRFA)

IUCN redlist When spawning, males typically arrive individually or small groups to establish territory and arrive earlier than female do. The females often come in large schools.  

Diet

https://www.whatsthatfish.com/fish/squaretail-coralgrouper/3818

The Squaretail Coral Grouper mainly feeds on fish. They hunt by creating a suction that pulls fish into their mouths and most often hunt alone.

(Squaretailed Coral Grouper | SCRFA)

Predators/Human Impact

There are several threats to Squaretail Coral Groupers. Squaretail coral groupers have a slow maturation and long life span, meaning that they cannot easily replenish their population when overfished. Overfishing is the leading cause to these groupers’ vulnerable status: fishing for the live reef food fish trade. Heavy fishing targets the spawning of Squaretail coral groupers. One of the most common member of the Plectropomus genus to be sold in restaurants https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=ec13869fa6565baa0716b0ef7f5c72aac6fca11d (for market data points)

They are considered artisanal fish and are among the top most desired and in-demand fish species in the fish-trade industry of Hong Kong  and sold at high value. (https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=da25dabd48fd4c295c8a4a823eaa3e1e5e807c4d) Most targeted fish by nighttime spearfishing or hook and line fishing since they are not active at night and stay in shallow reef areas. They are more abundant than other fish in their aggregation sites, which are the spawning area for these fish and other species, leading them to be more commonly hunted. Sales of fish are limited and there are catch bans during the reproductive seasons. The fish also exist in protected areas (IUCN redlist Conservation). They are also impacted by climate disturbances. There was a decrease in fishing from 1999-2000 but there still was a large volume of imported fish.

Other Information

There have been incidences of ciguatera from eating squaretail coral grouper, which is an illness caused by a toxin produced by a microalgae called Gambierdiscus toxicus. From 1997 to 2006, 2 cases were reported in Okinawa, Japan. (Oshiro et al)

Life cycle

Squaretail coral groups mature at around 2 years and live for around 13 years. They have a generation length of around 7 years (IUCN redlist).

Sources:

Khasanah, Miftakhul, et al. “Reproductive Biology of Three Important Threatened/Near-Threatened Groupers (Plectropomus Leopardus, Epinephelus Polyphekadion and Plectropomus Areolatus) in Eastern Indonesia and Implications for Management.” Animals (2076-2615), vol. 9, no. 9, Sept. 2019, pp. 643–643. EBSCOhost, https://doi.org/10.3390/ani9090643.

Rhodes, K. L., et al. “Reproductive Biology of Squaretail Coralgrouper Plectropomus Areolatus Using Age-Based Techniques.” Journal of Fish Biology, vol. 82, no. 4, 2013, pp. 1333–50. Wiley Online Library, https://doi.org/10.1111/jfb.12076.

Rhodes, Kevin L., et al. “Aligning Fisheries Management with Life History in Two Commercially Important Groupers in Chuuk, Federated States of Micronesia.” Aquatic Conservation: Marine and Freshwater Ecosystems, vol. 31, no. 3, 2021, pp. 605–19. Wiley Online Library, https://doi.org/10.1002/aqc.3452.

Squaretailed Coral Grouper | SCRFA. https://www.scrfa.org/aggregations/aggregating-species/plectropomus-areolatus-squaretailed-coral-grouper/. Accessed 17 Feb. 2023.

Ruppell, Eduard. “Plectropomus Areolatus Summary Page.” FishBase, https://www.fishbase.se/summary/6082.

Oshiro N, Yogi K, Asato S, Sasaki T, Tamanaha K, Hirama M, Yasumoto T, Inafuku Y. Ciguatera incidence and fish toxicity in Okinawa, Japan. Toxicon. 2010 Oct;56(5):656-61. doi: 10.1016/j.toxicon.2009.05.036. Epub 2009 Jun 9. PMID: 19520098.

Plectropomus areolatus (Squaretail Coralgrouper) (iucnredlist.org)