Daily food intake of Kajikia audax (Philippi, 1887) off Cabo San Lucas, Gulf of California, Mexico

Abstract

ABSTRACT.The daily food intake rates of the striped marlin, Kajikia audax (Perciformes: Istiophoridae), were estimated using qualitative and quantitative analyses of their trophic spectrum. We analyzed the stomach contents of 505 striped marlin caught by the sport fishing fleet off Cabo San Lucas, Baja California Sur, Mexico, sampled from October 1987 through December 1989. The most important preys were chub mackerel (Scomber japonicus), California pilchard (Sardinops caeruleus), and jumbo squid (Dosidicus gigas); together these represented ~55% of the striped marlin diet. The daily food consumption was estimated to be 2 kg per day, or ~3.6% of the mean body weight of K. audax. The total biomass of the prey consumed by the striped marlin during the 27 months of sampling around Los Cabos was estimated at 24.8 ton, of which the chub mackerel represented ~29% (7.2 ton), California pilchard just under 16% (3.9 ton), and jumbo squid ~10% (2.5 ton). The feeding habits of K. audax are discussed in terms of the distribution of the epipelagic (neritic and oceanic zones), demersal, and benthic prey, confirming that striped marlin migrate vertically and horizontally in search of their food. Keywords: billfish, striped marlin, diurnal variation, consumption, Cabo San Lucas, Gulf of California, Mexico.Tasa de consumo diario de alimento de Kajikia audax (Philippi, 1887) frente a Cabo San Lucas, golfo de California, México RESUMEN. Se estimó la tasa de consumo diario de alimento del marlín rayado Kajikia audax (Perciformes: Istiophoridae), sobre la base de análisis cualitativos y cuantitativos de su espectro trófico. Se analizó el contenido estomacal de 505 ejemplares capturados por la flota deportiva frente a Cabo San Lucas, Baja California Sur, México muestreados de octubre 1987 a diciembre 1989. Las presas más importantes fueron la macarela del Pacífico (Scomber japonicus), sardina monterrey (Sardinops caeruleus) y calamar gigante (Dosidicus gigas), que en conjunto representaron aproximadamente el 55% de la dieta. La tasa de consumo de alimento fue estimado en 2 kg diarios, lo cual representó aproximadamente el 3,6% del peso corporal de K. audax. La biomasa total de presas consumidas por el marlín rayado durante los 27 meses muestreados en la zona de Los Cabos fue estimada en 24,8 ton, de las cuales la macarela del Pacífico representó alrededor del 29% (7,2 ton), la sardina monterrey poco menos del 16% (3,9 ton) y el calamar gigante aproximadamente el 10% (2,5 ton). Los hábitos alimentarios de K. audax se discutieron según la distribución de las presas epipelágicas (neríticas y oceánicas), demersales y bentónicas; lo cual confirmó la conducta migratoria (movimientos verticales y horizontales) del marlín rayado en busca de su alimento.

Stable carbon and nitrogen isotope values of dorsal spine age rings indicate temporal variation in the diet of striped marlin (Kajikia audax) in waters around Cabo San Lucas, Mexico

“…Since the δ 15 N values in bands did not change significantly, we hypothesize that a shift in diet did not occur in this study. Abitía‐Cardenas et al . argued that striped marlin exhibited significant changes in their diet with age.…”

“…argued that striped marlin exhibited significant changes in their diet with age. Their findings are based on two samples groups: (a) marlin with postorbital length (PL) <158 cm sampled at Mazatlan, Mexico, together with marlin with PL <180 cm sampled at Los Cabos, Mexico that consumed less prey in both number and mass, and (b) marlin with PL >158 cm at Mazatlan and >180 cm PL at Los Cabos, Mexico, that consumed more prey in number and mass. It seems that change in prey related to maturity is sufficient to be reflected in the isotope ratio values.…”

“…This level of activity is consistent with Cabo San Lucas as a core area where striped marlin aggregate and feed . Despite the importance of this fishery, there remain gaps in our knowledge on the movements, foraging behavior and trophic status of the striped marlin . Understanding key biological characteristics is important to determine the status of striped marlin and it is necessary in order to practise sustainable management…”

Distribution of pelagic squids Abraliopsis Joubin, 1896 (Enoploteuthidae) and Pterygioteuthis P. Fischer, 1896 (Pyroteuthidae) (Cephalopoda, Decapodiformes, Oegopsida) in the Mexican Pacific

“…Abraliopsis affinis occurs in the tropical waters of the eastern Pacific Ocean, and is known from Chile, Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama and Peru. Abraliopsis falco has been reported from off the Baja California Peninsula (type locality and only area where it has been found so far) (Young et al 1998; Abitia Cardenas et al 2011). The third species, Abraliopsis felis , is found off the west coast of North America, from about 27° to 43°N (Young et al 1998).…”

“…Juveniles and adults of small squids are also important prey items for many species of pelagic fishes and some marine mammals (Fiscus et al 1989). Specimens of Abraliopsis affinis have been found to be part of the diet of the Peruvian hake ( Merluccius gayi peruanus Ginsburg, 1954) (Blaskovic 2011), of the striped marlin Kajikia audax (Philippi, 1887) from off Cabo San Lucas (Abitia Cardenas et al 2011), and of sharks in the Ecuadorian and Mexican Pacific (Galván-Magaña et al 2013). Abraliopsis sp.…”