Longspine Grunt

Longspine Grunt, Pomadasys macracanthus

The Longspine Grunt, Pomadasys macracanthus, whose common Spanish name is roncacho gordo, is a member of the Grunt or Haemulidae Family, known collectively as burros or roncos in Mexico. Globally, there are thirty-six species in the genus Pomadasys, five of which are found in Mexican waters, one in the Atlantic and four in the Pacific.

The Longspine Grunts have oblong and compressed bodies with a depth that is of 34% to 38% of standard length. They have an overall silvery appearance with four or five indistinct dark bars on their sides and a dark spot on the upper corner of their gill cover. They have a long straight oblique forehead and a short terminal mouth that ends well before the eyes and opens in the front. Their anal fin has 3 spines and seven or 8 rays with the second ray being exceeding long and stout; their dorsal fin is moderately notched with 12 spines and 13 rays; and their pectoral fins are very long reaching the anus. They are covered with scales.

The Longspine Grunts inhabit coastal seas over sandy substrates at depths up to 65 feet. They are known to enter estuaries and river mouths. They reach a maximum length of 35 cm (14 inches). Reproduction is oviparous with distinct pairing during breeding. They are a relatively unknown species and very little is known about their behavior patterns.

In Mexican waters the Longspine Grunts are found in all waters of the Pacific with the exception that they are absent from Magdalena Bay northward along the central and northwest coasts of Baja.

The Longspine Grunt can be confused with the Panamic Grunt, Pomadasys panamensis (13 dorsal spines; short pectoral fins), the Purplemouth Grunt, Pomadasys bayanus (elongated body; dark yellow pelvic fins), and the Sand Grunt, Pomadasys branickii (slender body; 13 dorsal spines; large eyes).

The Longspine Grunts are too small to be of interest to most but are sold on a limited basis in local markets within their range. From a conservation perspective that are considered of Least Concern, due to their wide distribution that extends as far south as coastal Peru.

f683-longspine-grunt-1Longspine Grunt, Pomadasys macracanthus. Fish caught within the coastal water of Magdalena Bay, Baja California Sur, April 2016. Length: 23.0 cm (9.1 inches). Caught with Jimmy Camacho, Jimmy’s Sportfishing, Puerto Adolfo Lopez Mateos, Baja California Sur, (Jimmyhcamacho@gmail.com, 613-114-0761; 612-204-1960).

Longspine Grunt, Pomadasys macracanthus. Fish caught from coastal waters off Santo Domingo, Baja California Sur, January 2017. Length: 33 cm (13 inches). Catch and photo courtesy of Brad Murakami, Surrey, British Columbia, Canada.

Longspine Grunt, Pomadasys macracanthus. Fish caught from coastal waters off Mazatlán, Sinaloa, October 2017. Length: 34 cm (13 inches). Catch, photo and identification courtesy of George Brinkman, Guelph, Ontario, Canada.