Larval fish assemblages in two nearshore areas of the Humboldt Current System during autumn-winter in northern Chile

Abstract

Ensambles de larvas de peces en dos áreas costeras del Sistema de Corrientes de Humboldt durante otoño-invierno en el norte de ChileResumen.-Se analizaron patrones espaciales y temporales en la composición de larvas de peces en dos áreas costeras pertenecientes al Sistema de la Corriente de Humboldt (HCS), en el norte de Chile. Cinco muestreos fueron realizados en Isla Santa María (ISM) y Punta Coloso (COL), Península de Mejillones. El ictioplancton fue recolectado cada 15 días durante la temporada otoño-invierno austral en 2014 (mayo a agosto). Un total de 412.410 larvas de peces pertenecientes a 36 taxa fueron identificadas, una alta abundancia comparada con otras regiones del HCS. Se registraron similares especies en comparación al centro de Chile, así como diferentes especies respecto del centro de Perú; se compartieron varias familias entre estas regiones del HCS y otros sistemas (por ejemplo, Sistema de Canarias). ISM fue dominado por especies del intermareal-submareal (por ejemplo, Helcogrammoides cunninghami), mientras que Engraulis ringens fue predominante en COL. Varias especies se correlacionaron positivamente con oxígeno disuelto (por ejemplo, Auchenionchus microcirrhis), así como con temperatura y transporte de Ekman (por ejemplo, Sebastes oculatus), mientras que otras se correlacionaron negativamente con los mismos parámetros ambientales (por ejemplo, Graus nigra). Los resultados sugieren que las larvas de peces podrían utilizar diferencialmente estas áreas, como refugio o zona de alimentación, y que los peces adultos estarían acoplando sus periodos de desove con procesos oceanográficos a corta escala temporal. Este estudio describe por primera vez los ensambles de larvas de peces en áreas costeras del norte de Chile, resaltando su importante rol en los primeros estados de desarrollo de los peces.Abstract.-This paper presents an analysis of spatial and temporal patterns in the fish larvae composition of two geographically adjacent nearshore areas within the Humboldt Current System (HCS), northern Chile. Five surveys were performed at Isla Santa María (ISM) and Punta Coloso (COL), Mejillones Peninsula. Ichthyoplankton were collected every 15 days in 2014 during the austral autumn-winter (May to August). A total of 412,410 fish larvae belonging to 36 taxa were identified, a high abundance compared with other HCS regions. Data also revealed similarities in species recorded compared with central Chile as well as differences compared with central Peru; a number of families were shared between these HCS regions and other systems (e.g., Canarias Current System). ISM was dominated by intertidal-subtidal species (e.g., Helcogrammoides cunninghami), while Engraulis ringens was most abundant at COL. Several species were positively correlated with dissolved oxygen (e.g., Auchenionchus microcirrhis), as well as temperature and Ekman transport (e.g., Sebastes oculatus), while the presence of others is negatively related to the same environmental parameters (e.g., Graus nigra). Results suggest that larvae differen...

Modelling seasonal patterns of larval fish parasitism in two northern nearshore areas in the Humboldt Current System

“…Along the HCS, a combination of low seawater temperatures (caused by upwelling events), thermal fronts (which increase coastal retention 21 ), slow larval fish growth rates (typically between 0.08 and 0.22 mm day −1 41 , 42 ) and long PLDs (~ 2 months) may account for copepod infestation on larvae of cryptobenthic fish. Other larval fish species with longer PLDs, such as Scartichthys viridis (72–124 days) and Calliclinus geniguttatus (83–135 days) 37 , however, were unparasitized during all study periods (see Supplementary Table S1 ), probably because they are advected offshore during their pelagic life, and the chance of parasitism is lower in oceanic waters 20 , 43 . Moreover, considering that (i) larval ectoparasites respond to non-specific visual stimuli, and (ii) spend approximately 2 days in the water column before detecting their host 16 , visual cues from the host would not be sufficient to explain why only five species of the total larval fish assemblage were parasitized.…”

“…The Humboldt Current System is a highly productive marine ecosystem that is largely influenced by constant coastal upwelling that maintains a high level of biological productivity 19 and supports a high abundance of larval fish species in the nearshore areas, especially in northern Chile 20 , which is characterized by a high retention of planktonic organisms and high food availability 21 . These local oceanographic conditions could favour the acquisition and retention of parasites in the water column and increase the probability of parasites encountering potential hosts.…”

Genetic structure analysis of Girella laevifrons populations in central Chile

“…There are several biological factors that could be determining the time and place of their settlement. One of such factors could be the selection of environments, a mechanism by which larvae sense their surroundings and select where they will recruit (Able, Wilber, Muzeni‐Corino, & Clarke, ; Bautista‐Romero, Funes‐Rodríguez, Jiménez‐Rosenberg, & Lluch‐Cota, ; Breitburg, ; Brochier et al, ; Buskey, Coulter, & Strom, ; Ekau & Verheye, ; Fiksen & MacKenzie, ; Gerlach, Atema, Kingsford, Black, & Miller‐Sims, ; Gonzalez et al, ; Paredes, Landaeta, & González, ). Such voluntary settlement could be due to the vertical migration of larvae, where they take advantage of current flows for horizontal movement (Chiswell & Roemmich, ; Crooks & Sanjayan, ; Gibson, ; Lobel & Robinson, ; Poulin et al, ).…”

Nuevos aires en la ictiología en Chile

“…Las interacciones ecológicas que tienen los peces con su medio van variando a lo largo de su ontogenia. Este volumen, en honor al Dr. Meléndez, es una oportunidad para conocer la composición y abundancia de los estados tempranos de peces marinos de zonas costeras, y el rol de las condiciones hidrográficas en su modulación, tanto en el norte de Chile, dominado por surgencias (Paredes et al 2018) como en el extremo sur, donde la circulación es de tipo estuarina (Castillo-Hidalgo et al 2018).…”