Hyporthodus niveatus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Actinopterygii Perciformes Epinephelidae

Scientific Name: Hyporthodus niveatus (Valenciennes, 1828)
Regional Assessments:
Common Name(s):
English Snowy Grouper, Seabass, Spotted Grouper
French Merou Neige
Spanish Cherna Machada, Cherna Pintada, Cherne Machada, Cherne Pintada, Machada, Mero
Epinephelus niveatus (Valenciennes, 1828)
Hyporthodus niveatus (Valenciennes, 1828)
Serranus niveatus Valenciennes, 1828
Taxonomic Notes: Smith (1971) synonymized the eastern Pacific species E. niphobles with E. niveatus (Heemstra and Randall 1993).

The type locality of Serranus margaritifer (Günther) is probably Guyana of South America (Heemstra and Randall 1993).

Recent publication changes the generic name from Epinephelus to Hyporthodus (Craig and Hastings 2007), and also. Recent publication suggests change in family name to Epinephelidae (Smith and Craig 2007).

Assessment Information [top]

Red List Category & Criteria: Vulnerable A2d+3d ver 3.1
Year Published: 2008
Date Assessed: 2008-01-01
Assessor(s): Thierry, C., Sadovy, Y., Choat, J.H., Bertoncini, A.A., Rocha, L., Ferreira, B. & Craig, M.
Reviewer(s): Sadovy, Y. & Moss, K. (Grouper and Wrasse Red List Authority)
Although H. niveatus is widespread, it has been heavily fished throughout its range and has declined at least 30% over the past 30 years and is predicted to continue to decline under current conditions. Although commercial quotas and trip limits had been enacted in the USA since 1993, stricter conservation measures for H. niveatus should be implemented because the existing population of this slow-growing, long-lived, protogynous species is still vulnerable to overfishing. In addition, fishery-independent figures suggest that the very low abundance of H. niveatus in the natural environment needs to be better protected from further fishing activities, especially if there is fishing on spawning aggregations. More information on its up-to-date stock, reproductive pattern (e.g., spawning behaviour, spatial and temporal aspects of distribution) sex ratio, knowledge of juvenile and adult distribution, population-age structure and management practices should be studied so as to have a continual monitoring of this vulnerable species.
Previously published Red List assessments:

Geographic Range [top]

Range Description:General
Hyporthodus niveatus is found in the western Atlantic from Massachusetts (USA) to the Gulf of Mexico, Bermuda, the Caribbean, southern Brazil (Heemstra and Randall 1993), and Uruguay.

Aruba, Bahamas, Belize, Bermuda, Brazil, Colombia, Costa Rica, Cuba, French Guiana, Grenada, Guatemala, Guyana, Honduras, Jamaica, Mexico, Netherlands Antilles (Curaçao), Nicaragua, Panama, Puerto Rico (stray), Suriname, Trinidad and Tobago, United States, Uruguay, and Venezuela.
Countries occurrence:
Argentina; Aruba; Bahamas; Barbados; Belize; Bermuda; Bonaire, Sint Eustatius and Saba; Brazil; Colombia; Costa Rica; Cuba; Curaçao; French Guiana; Grenada; Guatemala; Guyana; Honduras; Mexico; Nicaragua; Panama; Saint Lucia; Saint Vincent and the Grenadines; Suriname; Trinidad and Tobago; United States; Uruguay; Venezuela, Bolivarian Republic of
FAO Marine Fishing Areas:
Atlantic – western central; Atlantic – southwest
Additional data:
Lower depth limit (metres):525
Upper depth limit (metres):30
Range Map:Click here to open the map viewer and explore range.

Population [top]

The most common deep-water grouper throughout its range, although in decline in association with heavy fishing.

From catch curve estimates, the mortality of H. niveatus increased from 0.19 to 0.32 in the headboat fishery in 1972 to 1978, but remained stable at 0.24 to 0.25 in the commercial fishery from 1977 to 1979 (Matheson and Huntsman 1984).

Huntsman et al. (1999) stated that H. niveatus was very rare and that only small individuals were observed in the US South Atlantic.

Fishery-independent Data
Studies on the populations of H. niveatus in the USA revealed that its population has declined since 1985.

Fishery-independent data by country
Based on the information from Reef Environmental Education Foundation (REEF), the sighting frequency (SF; a value calculated as dividing the number of survey with H. niveatus encountered [n] by the total number of surveys carried out in a particular year [N]) of H. niveatus in the tropical western Atlantic stayed almost zero from 1993 to 2005 (except 0.01% to 0.04% in 2002 to 2004) (; accessed on 2nd Mar 2006).

See the Supplementary Material for Table 1: Sighting frequency of H. niveatus based on Reef Environmental Education Foundation (REEF) underwater visual census.

Adrian's Mark (2,700 sq. m), Onslow Bay, North Carolina, USA
Based on the catches (from a previously unexploited group of H. niveatus) from 21 trips by two fishing vessels (fished at depths of 137-194 m) from June 1985 to April 1986, H. niveatus comprised 91.7% of 1,094 fish caught, contributing over 30% of the total amount of H. niveatus landed in North Carolina (Epperly and Dodrill 1995).

Epperly and Dodrill (1995) estimated the initial exploitable biomass ranged from 29.2–30.8 tonnes (eviscerated weight), at a density of about 11 kg per sq. m. Epperly and Dodrill (1995) also found that not only had catch rates declined from 8.10 fish (68.8 kg) per drop in June 1985 to 1.25 fish (6.6 kg) per drop in September 1985, but also that of the mean fish size. In that study, the rate of decline in numbers between 28 June and 7 August 1985 (40 days) was estimated to be 3% of the population daily by fishing. By early August 1985, over 60% of the exploitable biomass was found to be removed; and within a year, over 80% had been removed (Epperly and Dodrill 1995).

North Carolina and South Carolina, USA
Wyanski et al. (1999) suggested that the population of H. niveatus was overfished based on the following:

1. size at age of fish caught with longlines and snapper reels had increased noticeably since the 1980s, which could be a density-dependent population response to a decrease in competition for resources;

2. 81% of the fish caught with commercial longlines in 1993 to 1994 (N=809) were aged to six years, with immature females the majority (56%) (female maturity is about three years);

3. the percentage of males in the population (based on 599 sexually mature fish) seemed to have decreased significantly from 7-23% in the 1970s and 1980s to 1% in the 1990s; and

4. mean length of fish landed in the longline fishery had steadily decreased from 65 to 80 cm TL in the early 1980s to 50 to 60 cm TL in the mid-1990s.

Broward County, Florida, USA
Based on over 1,100 visual fish census on natural and artificial reefs at depths of 7 to 23 m from 1995 to 2002, only eight juvenile H. niveatus were recorded from seven visual point counts (Arena et al. 2004).

Fishery-dependent Data
Fishery-dependent data by country

Southeast Brazil (23° to 26°S)
From 1986 to 1995, H. niveatus comprised 9.9% of the total catch by bottom line fisheries (201-650 m). The largest catch was made between 201 and 300 m, with a mean CPUE of 0.1 kg per hook-day (Paiva and Garcez 1998).

Among the species observed in the industrial landings in south Brazil (Rio Grande do Sul), from 1989 and 1999, H. niveatus (cherne-verdadeiro), and was captured frequently during the 90s, but was never abundant (1 to 30 specimens per boat) (Monica Brick, pers. comm.).

Southeast Brazil (18° to 26°S)
From 1986 to 1995, H. niveatus comprised 12.1% of the total catch of benthic fishes by liners (Paiva and Andrade-Tubino 1998).

Annual landings in Santa Catarina (south Brazil) for H. niveatus is as follows 14.15t (2002), 1.76t (2003), 0.54t (2004), 1.70t (2005) and 4.50t (2006) (GEP/UNIVALI, 2006). For São Paulo (southeast Brazil), 8.45t (1999), 5.38t (2000), 0.37t (2001), 0.51t (2003), 0.34t (2004) and 0.32t (2005) (Instituto de Pesca 2006).

In areas where it has been fished beyond economic viability, recovery has been slow.

According to the NMFS annual commercial fishery landings of H. niveatus, the quantity between 1981 and 2004 ranged from 44.2 to 306.7 mt. From 1999 to 2004, an annual average of 232.6 mt of E. niveatus was landed (, accessed on 5th Jan 2006).

See the Supplementary Material for:
Table 2: NMFS annual commercial fishery landings of H. niveatus (1981-2004); and
Table 3: Catch and revenue of landings of H. niveatus from the South Atlantic.

USA (Gulf of Mexico region, including all of Monroe County)
According to NMFS, the annual recreational harvest estimates of both number (N) and weight of H. niveatus averaged 7,619 fish and 15,641 kg in 1996 to 2005. Landing peaked at 87,298 fish and 280,263 kg in 1981. (Note: there are very large proportional standard errors (PSE) associated with the annual estimates of landings, which suggest these are rare-event landings in the recreational fisheries of the Gulf of Mexico.) (Tom Sminskey, Statistician of the Fisheries Statistics Division of the NMFS, pers. comm. on 15th Mar 06)

See the Supplementary Material for Table 4: NMFS Gulf of Mexico region, including all of Monroe County - annual recreational harvest estimates of both number (N) and weight of H. niveatus.
For further information about this species, see 7861_Hyporthodus_niveatus.pdf.
A PDF viewer such as Adobe Reader is required.
Current Population Trend:Decreasing
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:General
Adult H. niveatus occur offshore on rocky bottoms at depths of 30 to 525 m, but are most common between 100 and 200 m. Juveniles may be found inshore and are often reported from the northeastern coast of the USA (Heemstra and Randall 1993). Wyanski et al. (1999) reported that larger adults were caught more frequently in waters deeper than 100 m in South Carolina. Jones et al. (1989) observed H. niveatus utilizing shelter around rock ridge habitat in the northwestern Gulf of Mexico, suggesting there would be a resource partitioning of habitat space utilization or shelter between H. niveatus and H. flavolimbatus.

Maximum size attained is about 120 cm TL (Heemstra and Randall 1993). Recorded maximum weight is 30 kg (Heemstra and Randall 1993). Maximum age attained is 29 years (Wyanski et al. 1999). Full recruitment into the fishery occurred at 575–600 mm TL and at age eight years (Moore and Labisky 1984). Ximenes-Carvalho et al. (1999) suggested that H. niveatus was long-lived (tmax=46.4 years) and had annual natural mortality (M) of 0.170.

Length-age relationship
Based on an otolith study of 536 H. niveatus collected from the US South Atlantic Bight from 1972 to 1979, the von Bertalanffy growth equation of the was TL(mm)=1255 (1-e(-0.074(Age+1.92)) (Matheson and Huntsman 1984).

Based on 178 fish from relatively unexploited population in the lower Florida Keys, the von Bertalanffy growth equation for H. niveatus was 1,320 mm TL (1-e(-0.087(Age+1.013)) (Moore and Labisky 1984).

According to otolith-based age studies of H. niveatus collected by commercial and research vessels, the von Bertalanffy growth equations calculated in different sampling periods were (Wyanski et al. 1999):

1993-94 by snapper reels (commercial catch; n=311) = 1201 mm TL (1-e(-0.103(Age+1.149))

1982-85 by longlines and Kali poles (research; n=163) = 948 mm TL (1-e(-0.122(Age+0.668))

1993-94 by longlines (commercial catch; n=1218) = 1117 mm TL (1-e(-0.119(Age+1.409))

Annual mortality of the relatively unexploited stock was calculated to be 16% by catch-curve analysis (Moore and Labisky 1984), which was lower than the total annual mortality rates of 21–22% for commercially fished stocks in North Carolina and South Carolina during the late 1970s (Matheson 1981).

Adults feed mainly on fishes, gastropods, cephalopods, and brachyuran crustaceans (Heemstra and Randall 1993).
Examination of intestinal contents revealed that E. niveatus feeds on fish (47% by number), cephalopods (18%) and brachyuran crabs (Bielsa and Labisky 1987).

Based on a study on stomach content, Weaver and Sedberry (2001) recorded that the diet of H. niveatus included swimming crab Portunus spinicarpus (90%), other benthic crustaceans, fishes (6%) and squids (2%).

Sexual pattern
Hyporthodus niveatus was suggested to be a protogynous hermaphrodite by the presence of early males aged 7, 8 and 9, showing evidence of recent sexual transformation (no transitional was found) (Moore and Labisky 1984).
Wyanski et al. (1999) concluded that H. niveatus is protogynous based on the size (767-1090 mm) and age (8-29 year) of 97 males and the capture of two transitionals (787 mm TL, age unknown and 1000 mm TL aged 13).

Reproductive biology
81% of 144 females reached sexual maturity by age 4–5. Males could not be found until age six, but males comprised 40% of all fish of age eight or older (Moore and Labisky 1984). Moore and Labisky (1984) also suggested that sexual transition occurs principally within 3–4 years after the females reach sexual maturity in the Florida Keys.

Based on samples collected in the Carolinas from 1991 to 1995, Wyanski et al. (1999) found that female H. niveatus matured at lengths from 451 to 575 mm TL (ages 3–7). Mature gonads were found in 4% of the females at age three, 52% at age five, 95% at age seven, and 100% at ages older than seven. The smallest mature female was 469 mm TL and the largest immature female was 575 mm TL (Wyanski et al. 1999).

In the Florida Keys, H. niveatus were found in spawning condition from April to July (Moore and Labisky 1984).

On the upper continental slope off South Carolina at depths of 176–232 m, H. niveatus were observed to be in spawning condition from April to September (Wyanski et al. 1999).

Wyanski et al. (1999) suggested that H. niveatus might form spawning aggregations.
For further information about this species, see 7861_Hyporthodus_niveatus.pdf.
A PDF viewer such as Adobe Reader is required.
Generation Length (years):<10years

Use and Trade [top]

Use and Trade: Consumed as food, with commercial importance for the stocks off the southeast coast of the USA (North Carolina to Georgia), Florida west coast, lower Florida Keys, Honduras/Nicaraguan shelf, and off Panama, Colombia, and Venezuela (Heemstra and Randall 1993). Harvest by the recreational sector was considered to be relatively minor (SAFMC 2005).

Threats [top]

Major Threat(s): General
Caught with hook-and-line, bottom longlines, with traps and trawlings (Moore and Labisky 1984, Heemstra and Randall 1993).

Trawls operated at 25-45 m depths poses a threat to juvenile survival (Moore and Labisky 1984).

Yield-per-recruit model for H. niveatus indicated that the headboat and commercial fisheries were harvesting 60–80% of the maximum available yield per recruit (Matheson and Huntsman 1984).

In Onslow Bay, off the central North Carolina coast, the rate of decline in number between 28 June and 7 August 1985 (40 days) was estimated to be 3% of the population was removed daily by fishing. By early August 1985, over 60% of the exploitable biomass was found to be removed; and within a year, over 80% had been removed (Epperly and Dodrill 1995).

Wyanski et al. (1999) reported that H. niveatus is susceptible to rapid depletion in a localized area through fishing efforts.

Musick et al. (2000) considered that the risk factors of H. niveatus included low productivity, protogyny, spawning aggregations, and that the species is vulnerable to extirpation in United States waters where populations are severely depleted and where the percentage of males in populations have declined significantly (Wyanski et al. 1999; Huntsman et al. 1999).

Arena et al. (2004) suggested that the high demand for H. niveatus with its naturally slow growth rates made this species extremely susceptible to overfishing.

H. niveatus occurs at depth outside most established marine protected areas within its range.

Conservation Actions [top]

Conservation Actions: General
In the US, the species has been monitored and had conservation measures applied directly to manage the fishery since the early 1990s.

In Brazil,  Hyporthodus niveatus was a frequent species and was often landed with Polyprion americanus (Polyprionidae) (DD) (Sadovy 2003), but was likely commonly misidentified and quantified. In 2005, a 10-year-ban for P. americanus fisheries was instituted by the Brazilian Environment Ministry (BRASIL/MMA 2005) that may afford H. niveatus some protection from fishing.

1. US Amendment #6 (1993): commercial quotas and trip limits enacted (SAFMC 2005).

2. US Amendment #11 (1998): H. niveatus determined to be overfished (static SPR = 5-15%) (SAFMC 2005).

3. Preferred Alternatives in US Amendment 13C:

Reduce the annual commercial quota from 344,508 lbs gutted weight (406,519 lbs whole weight; implemented in 1994) to 84,000 lbs gutted weight (99,000 lbs whole weight). Prohibit purchase and sale, and prohibit harvest and/or possession of H. niveatus over the bag limit after the quota is taken. Specify a commercial trip limit of 10 fish until the quota is met (SAFMC 2005). An annual quota of 245,082 kg, with a trip limit of 1,134 kg (SAFMC 1993).

Limit the possession of H. niveatus to one per person per day within the five-grouper per person per day aggregate recreational bag limit.

4. Classified as endangered by U.S. Fish and Wildlife Service (USFWS) concept of District Population Segments (DPS) (Musicket al. 2000).

Suggested measures
Wyanski et al. (1999) suggested that the age composition of H. niveatus landings should be monitored because only 19% of the fish caught (n=809) by longlines in South Carolina were older than six years. This further emphasizes the problem of removal of females, as Moore and Labisky (1984) could not find a male until age 6 years. Juveniles would have to be protected to ensure recruitment to the adult population through developmental migration (Moore and Labisky 1984).

Citation: Thierry, C., Sadovy, Y., Choat, J.H., Bertoncini, A.A., Rocha, L., Ferreira, B. & Craig, M. 2008. Hyporthodus niveatus. The IUCN Red List of Threatened Species 2008: e.T7861A12857720. . Downloaded on 23 September 2018.
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