Snowy Grouper, Hyporthodus niveatus
Snowy Grouper, Hyporthodus niveatus, Juvenile. Fish caught from coastal waters off Long Island, New York, August 2022. Length: 8.8 cm (3.5 inches). Catch, photograph and identification courtesy of Aidan Perkins, Long Island, New York.
Snowy Grouper, Hyporthodus niveatus. Two photographs of the same fish caught from coastal waters off Islamorada, Florida, April 2012. Length: 71 cm (2 feet 4 inches). Weight: 9.1 kg (20 lbs). Catch, photograph, and identification courtesy of George Brinkman, Guelph, Ontario, Canada.
The Snowy Grouper, Hyporthodus niveatus, is a member of the Grouper or Epinephelidae Family, and is known in Mexico as cherna pintada. Globally, there are fourteen species in the genus Hyporthodus, of which seven are found in Mexican waters, four in the Atlantic and three in the Pacific Ocean.
The Snowy Grouper has a robust compressed oval body that is deepest at the origin of their dorsal fin. Adults are dark brown and the edge of their spiny dorsal fin is black. Juveniles are dark brown with prominent white spots in vertical rows on the rear of their head and body extending onto the dorsal fin; these spots fade quickly upon death. Their caudal and pectoral fins are transparent with a yellowish tinge. They have a black saddle on their upper caudal fin base that reaches the lateral line. They have a large terminal mouth equipped with depressed teeth on the sides and roof of the mouth. Their anal fin has 3 spines and 9 rays; their caudal fin is rounded in juveniles and straight to concave in adults; their first dorsal fin has 11 spines, with the third or the fourth being the longest; their second dorsal fin has 13 to 15 rays; and, their pectoral fins are behind their pelvic fins. In juveniles the pelvic fins are longer than the pectoral fins. They have 22 to 26 gill rakers. They are covered with rough scales.
The Snowy Grouper is a demersal species that is found at depths between 30 m (100 feet) and 488 m (1,600 feet) over and within rocky structures. Juveniles are found inshore in waters as shallow as 30 m (100 feet). They reach a maximum of 1.22 m (4 feet 0 inches) in length and 32 kg (70 lbs) in weight. As of January 1, 2024, the International Game Fish Association world record stood at 31.95 kg (70 lbs 7 oz) with the fish caught from coastal waters off Norfolk, Virginia in May 2011. They feed on cephalopods, crustaceans, fish, and gastropods. They are considered to be a top-level predator and the adults are subject to limited predation. Reproduction occurs as sequential hermaphroditism with all fish born as females and changing to males around age 7. Females release pelagic eggs in multiple batches and the larvae are pelagic. They have a lifespan of up to twenty-nine years. The Snowy Grouper is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.
The Snowy Grouper is a resident of all Mexican waters of the Atlantic Ocean including the Gulf of Mexico and the Caribbean.
The Snowy Grouper is an easy fish to identify due to its white spotting pattern. Adults can be confused with the Warsaw Grouper, Hyporthodus nigritus (very long second dorsal spine). They are very similar to, and considered by some scientists to be the same species as the Star-studded Grouper, Hyporthodus niphobles from the Pacific Ocean.
From a conservation perspective the Snowy Grouper is currently considered to be Vulnerable with significant declines in their populations over the last fifteen years. Historically they have been the most common grouper throughout their range and considered one of the more important species of groupers in Mexican deep waters of the Gulf of Mexico. They are a focus of handline, longline (up to 1,200 hooks per set) and gill net commercial fishermen and recreational anglers. They are considered a quality food fish and sold fresh commercially. They are caught at levels of up to 140 metric tons (280,000 lbs) annually in the Gulf of Mexico, with the majority of the catch being older and larger males. The size and age of the landed fish have diminished significantly over the past decade. Intensified fishing pressure occurs during aggregation and spawning windows with larger males primarily removed from residual populations. They are a long-lived and non-migratory hermaphroditic species that is very slow to mature. Efforts to regulate the fishery in the United States are in place and include inshore water closures, bans on fishing with bottom gear, establishment of no fishing marine reserves, seasonal closures, and bag limits, however, such controls are absent from other parts of their known range. They are also prone to habitat destruction caused by trawls targeting more abundant species found at similar depths including various groupers and tilefish. At present this species is extinct in some parts of its historical range and scientific monitoring of its status throughout most of its current range is inadequate.