Zooplankton volumes, distribution, and abundance of ichthyoplankton, euphausiids, and paralarvae, summer 2018

Abstract

volume of zooplankton ranged from 1.6 to 55.0 mL/sample, with higher values north of the sampling area. The main families of ichthyoplankton were Phosichthyidae (84.42%), Myctophidae (62.34%), Engraulidae (22.08%), Bathylagidae (18.18%). Vinciguerria lucetia was distributed throughout the study area. Abundance varied between 3 and 52,608 eggs/m2 and between 3 and 300 larvae/m2. The presence of Engraulis ringens eggs and larvae was frequent between grades 8 and 10°S, fluctuating between 63 and 9,438 eggs/m2 and between 3 and 87 larvae/m2, representing 9.68% and 0.21% of the total ichthyoplankton abundance, respectively. In Scombridae, Auxis rochei larvae were frequent in 10.39% of the total stations and were distributed between 5°S and 9°S, Scomber japonicus larvae frequency was 3.90% and were located in 5°S; Trachurus murphyi larvae had frequency of 1.30% and were located in 5°S. Furcilies and euphausiid juveniles were abundant and frequent; Euphausia juveniles were representative. Paralarvas of the Argonautidae family reached 96.92% frequency, with total abundance of 1,665 Ind/m2, Argonauta was distributed throughout the study area with abundances greater than 100 Ind/m2 between Supe and Huacho, and south of Independencia Bay. The zooplanktonic communities were mainly associated with SSA and the mixture with FCF. The dynamics of the AES remained north of 6°S.