Pacific dog snapper

Lutjanus novemfasciatus is a snapper of the family Lutjanidae native to the eastern Pacific ^[1],[2]. It is a large fish: FishBase gives a maximum of 1.7 m in total length ^[2]. Adults keep to rocky and coral reefs near the coast, while juveniles grow up in mangrove estuaries and river mouths ^[2]. In Peru, the management plan of the Reserva Nacional Mar Tropical de Grau calls it pargo gigante and does not allow it to be taken anywhere in the Arrecifes de Punta Sal sector ^[3].

The genus name, Lutjanus, comes from the Malay ikan lutjan, the name of a fish ^[2]. Gill described the species in 1862 from material taken at Cape San Lucas, Mexico, and Mesoprion pacificus and Lutjanus prieto are later synonyms ^[4]. Juveniles show 9 dark bars crossing the body ^[4].

The snout is rounded, the tooth patch on the vomer is crescent-shaped with no backward extension, and the tongue carries one or more patches of granular teeth ^[4]. The dorsal fin has 10 spines and 13 or 14 soft rays, the anal fin 3 spines and 8 rays, and the tail is truncate or only slightly concave; above the lateral line the scale rows run upwards at a slant ^[4].

Back and flanks range from dark olive brown to coppery red or purplish, the belly is whitish and the inside of the mouth is reddish yellow ^[4]. Juveniles bear 9 dark bars, with a black margin on the spiny dorsal fin and over most of the anal fin ^[4]. Set beside the juveniles of two other snappers from the same Mexican lagoon, its young are slimmer and have bigger teeth ^[5].

Similar species

• Lutjanus colorado: Also mainly red and also with 10 dorsal spines, but its scale rows above the lateral line are horizontal rather than slanted ^[4].
• Lutjanus peru: Uniformly reddish, with a diamond-shaped vomerine tooth patch, and large adults have grooves from the eye to the nostrils and at the top of the preopercle ^[4].
• Lutjanus viridis: Yellow, with 5 dark-edged bluish stripes along the sides, and no teeth on the tongue ^[4].
• Lutjanus argentiventris: Mostly yellow, and its scale rows above the lateral line are horizontal ^[4].

It ranges through the eastern Pacific from northern Mexico to northern Peru, from the surface down to 60 m, mostly between 5 and 12 m ^[2]. In 1985 the FAO snapper catalogue gave its range only as far as Panama and treated reports from northern Peru as unconfirmed ^[4]. It also lives in the mangroves of Isabela Island, Galapagos ^[6].

Adults live over hard ground, on rocky and coral reefs close to shore ^[4],[2]. Juveniles turn up in mangrove estuaries and river mouths ^[2]; in the Barra de Navidad lagoon, Jalisco (Mexico), they were caught over muddy bottoms 1 to 2 m deep ^[5].

In two mangrove creeks on Isabela Island, where salinity swings twice a day from under 10 practical units, and under 2 in one of them, to over 35, 20 juveniles were fitted with acoustic transmitters in July 2013 ^[6]. Over the following year they stayed in the creeks about 93 % of the time around high tide and 91 % around low tide, and at low water they seemed to shelter from the current among the mangrove prop roots ^[6].

It reaches 1.7 m in total length and a published maximum weight of 35.7 kg ^[2]. The 1985 FAO catalogue, by contrast, gave a maximum total length of about 65 cm ^[4].

In the Barra de Navidad lagoon, the diet of 183 juveniles 1.2 to 20 cm long was split almost evenly between decapods, at 50 %, and fish, at 44 % ^[5]. In this species the size of the fish eaten rose with the size of the predator, while the size of the decapods showed no such link ^[5].

It is a carnivorous predator that eats large invertebrates such as crabs and shrimps, as well as fish ^[2]. Its juveniles hunt the same prey groups as those of Lutjanus argentiventris and Lutjanus colorado, but they eat more fish, which the authors put down to a slimmer body and larger teeth ^[5].

In the Galapagos mangroves, more than 80 % of the tagged juveniles were still being detected over the year of tracking; the authors read that high survival as a sign of the shelter mangroves provide ^[6].

The IUCN Red List classes it as Least Concern (LC) ^[7]. FishBase rates its vulnerability to fishing at 81 out of 100 and its resilience as very low, with a minimum population doubling time of more than 14 years, though both are preliminary estimates ^[2].

In the Reserva Nacional Mar Tropical de Grau, the 2026 management plan reports that snappers (Lutjanus spp.) are caught with bottom gillnets, spearfishing and hook-and-line, and incidentally by illegal purse seining and bottom trawling, and that their populations have fallen significantly ^[3]. The same plan does not allow the pargo gigante to be taken anywhere in the Arrecifes de Punta Sal sector ^[3] and lists it among the species that may not be caught in that sector's recovery zones ^[3].

Not medical advice. For a sting, a poisoning or an allergy, seek medical care.

In the Navachiste lagoon complex, Mexico, organochlorine pesticides were measured in fillets of Lutjanus novemfasciatus, Lutjanus colorado and Lutjanus argentiventris collected between February 2012 and February 2013 ^[8]. Endosulfan sulfate, δ-HCH and heptachlor epoxide were the compounds found most often and at the highest levels; for monthly portions, mean levels of HCH, chlordane and heptachlor exceeded the minimal risk levels for cancer, so the authors regard eating these snappers often as a health risk ^[8].

It is fished with nets, trawls and handlines, and sold fresh or frozen ^[4]. FishBase lists it as a commercial species and a gamefish, in a high price category ^[2].

In the recovery zones of the Arrecifes de Punta Sal sector, where it is protected, there is occasional recreational diving, boating and sport fishing ^[3].

The 2026 management plan of the Reserva Nacional Mar Tropical de Grau names the pargo gigante among the key or threatened species of the Arrecifes de Punta Sal sector, whose rocky reefs shelter most of the threatened fish and invertebrates ^[3]. The sector's two recovery zones, of 379.24 ha and 199.45 ha, were chosen because they hold most of the rocky reefs and once supported the healthiest fish and invertebrate populations ^[3]. There, for the time being, fishing is allowed only with handline and hook from a boat, or with handline or rod from the shore ^[3].