Parasite richness in fish larvae from the nearshore waters of central and northern Chile

Abstract

In the present study, we determine the presence of parasites in fish larvae collected from nearshore waters along the northern and central coast of Chile. The parasites were identified to the lowest possible taxonomic level based on morphological and molecular analyses. The fish sample was composed of 5 574 fish larvae. Of these, 3% harboured only larval ectoparasitic copepods whereas no endoparasites were found in the 1 141 fish evaluated for this group of parasites. The parasitic copepods collected were initially classified as 'morphotypes' according to differences in morphological characteristics. They were then analysed using molecular techniques based on the 28S and COI genes. Seven morphotypes of parasitic copepods (mostly at chalimus stages) were recognised: two of the morphotypes belonged to Pennellidae Burmeister, 1835, three to Caligidae Burmeister, 1835 and two were not identified. Only five morphotypes of copepods were analysed using molecular sequences, which confirmed the existence of six species: two pennellids of the genus Trifur Wilson, 1917 and two caligids of the genus Caligus Müller, 1785, plus two additional species that were morphologically different from these taxa. The pennellids were present in several fish species, being generally more prevalent than the caligids, in both the central and northern localities of Chile. Multispecies infections in larval fish were infrequent (< 1%). We conclude that fish larvae were rich in parasites, considering that these hosts exhibited small body sizes and were very young. We suggest that fish larvae could play a role, as intermediate hosts, in the life cycle of the parasitic copepods found.

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

“…Studies of copepods parasitizing fish larvae around the world are scarce. However, a few studies have reported parasitic larvae of the family Pennellidae on larval fish belonging to different families 4 , 5 , 7 . Our study adds more data to the record of such ectoparasites; this work documented ectoparasitic pennellid larvae ( Trifur sp.)…”

“…The ectoparasites were then separated and identified as belonging to the family Pennellidae and the genus Trifur based on morphological characteristics such as body shape, appendages, buccal structures, legs, genital complexes, and abdomens 5 . Additionally, molecular analysis based on the Cytochrome Oxydase I (COI) gene was performed to support the identification of the larval parasites collected from the larval fish species.…”

“…Individuals at the larval stages of the ectoparasitic copepod of the genus Trifur (Copepoda: Pennellidae) have been reported to parasitize fish larvae from the families Clinidae, Engraulidae, Gobiidae, Gobiesocidae, Labrisomidae, Tripterygiidae, and Pinguipidae 5 , 13 . However, there are no records of Trifur spp.…”

Parasitic copepods affect morphospace and diet of larvae of a temperate reef fish

“…All G. marmoratus larvae were observed and photographed under an Olympus SZ‐61 stereomicroscope (http://www.olympus.com) to separate and preserve each parasitized larva into individual containers for further analysis. Each ectoparasite was identified to the lowest possible taxon based on mouthparts and appendages (Castro & Baeza, , ; Muñoz et al ., ). Additionally, all ectoparasite copepods were measured in its maximum width and length of the prosome to the nearest 0·01 mm under a stereomicroscope Olympus SZ‐61 with a video camera Moticam 2500 (5·0 Mpixel) connected to a PC with Moticam Image Plus 2.0 software (Motic(R); http://www.moticeurope.com).…”

“…This species has high ectoparasite prevalence (12-14%) and high intensity (1-8 ectoparasites) during the larval pelagic stage Palacios-Fuentes et al, 2015). Larvae are parasitized by two copepod genera, Trifur (Pennellidae) and Caligus (Caligidae) (Muñoz et al, 2015b) and it has been described that pennellid copepod burden is positively correlated with larval density .…”