Prevalence and Species Identity of Trypanorhyncha in Cultured and Wild Amberjack, Seriola spp. in Hawaii – Implications for Aquaculture

Abstract

The advent of molecular technologies allow for identification of organisms that were previously challenging or not possible. Conventional polymerase chain reaction analyses of a segment of the small subunit ribosomal RNA gene from trypanorhynch plerocerci obtained from cultured and wild caught amberjacks, Seriola dumerili, and Seriola rivoliana of the family Carangidae from Hawai‘i and Japan were found to be 100% identical, indicating that the cestodes from Japan and Hawai‘i are the same species, Protogrillotia zerbiae. The prevalence of the trypanorhynch plerocerci found in the musculature of Hawai‘i wild‐caught S. dumerili and S. rivoliana was 86.9 and 72.7%, respectively. In stark contrast, no trypanorhynch plerocerci have been detected in S. rivoliana cultured in Hawai‘i and they are only rarely seen in S. dumerili cultured in Japan. Trypanorhynch plerocerci are part of a complex life cycle that involves the transmission in at least two intermediate hosts before finally residing in a host shark species. The results of this study indicate that artificial propagation of the amberjacks using manipulated diets has most likely disrupted the life cycle of this tapeworm, thus reducing the prevalence of this parasite in farmed amberjacks and enhancing the marketability of cultured amberjack.

Is seeing believing? Diver and video-based censuses reveal inconsistencies in roving predator estimates between regions

“…Seriola spp.) are known to occur in greater numbers (Tamaru et al 2016). Towed-divers also observed occasional changes in predator behavior, particularly in high-density areas where, at times, aggregations of predators may trail divers during surveys (J. Asher pers.…”

“…It is important to note that while tracking and mark-and-recapture techniques represent viable and valuable methods to assess roving predator populations, they are not a panacea because they remain susceptible to their own information gaps, e.g. potential omission of inter-island predator movements (Tagawa & Tam 2006, Meyer et al 2007a, Nadon 2017.…”

Infectious diseases and treatment solutions of farmed greater amberjack Seriola dumerili with particular emphasis in Mediterranean region

“…In addition to wild-caught fish, fish produced in aquaculture may present a food safety risk (Clausen et al, 2015). Parasitic cestodes have evolved very complex life cycles, involving an aquatic larval stage followed by one or more larval stages spent in intermediate hosts (Tamaru et al, 2016). The order Trypanorhyncha is a highly diversified parasitic group of cestodes infecting mainly elasmobranches where fish may serve as intermediate hosts (Ogawa et al, 2012).…”

Why Interdisciplinary Research is Critical for the Growth and Development of Aquaculture

“…For example, we now know that studies on nutrition of aquatic animals frequently require understanding of the effects on gut microflora or on immune systems that may require analyses and interpretation by fish health scientists (recent examples in JWAS include: Arab and Islami ; Barros et al ; Kokou et al 2015; Sangma and Kamilya ; Xu et al ) or effects of diet on gene expression (such as in Li et al ). The development of novel techniques to prevent and treat diseases often requires the skill of molecular biologists and geneticists (as in Alvarez‐Ruiz et al ), while molecular techniques can identify epidemiological patterns of parasites as related to aquaculture production (Tamaru et al ). Analyses of new production systems and management strategies will be of little value to aquaculture producers without an analysis of the economic effects and trade‐offs (a recent example in this journal is Hernández et al ).…”