Long-term implantation of acoustic transmitters induces chronic inflammatory cytokine expression in adult rainbow trout (Oncorhynchus mykiss)

Abstract

Highlights Presence of an acoustic transmitter did not influence surgical site healing rate  Tags were encapsulated inside the peritoneum as early as 15 days post-surgery  Spleen and surgical site cytokine expression was not influenced by tag presence  Tag presence increased inflammatory cytokine expression in peritoneal immune cells  At day 70 mature females had lower cytokine gene expression when compared to males AbstractTelemetry transmitters are frequently used in studies of wild fish migration and behavior. Although the effects of surgically implanted transmitters on survival, tag retention, healing and growth have been studied, there has been little research regarding the potential immune response induced by these transmitters. In the current study, mature rainbow trout received either surgical implantation of an acoustic transmitter or a sham surgical procedure. These fish were then sampled over a 10-week period so that pro-inflammatory cytokine expression in the spleen, peritoneal cavity lymphocytes and muscle at the surgical site could be analyzed. There were no significant differences in transcript expression for the spleen and muscle tissue between fish that had a transmitter and those that received the surgical procedure alone. However, transmitter presence significantly increased the expression of IL-6, IL-1β and TNFα in the peritoneal cells at 10 weeks indicating that tagged fish may be coping with chronic inflammation. Furthermore, tagged male fish had a higher inflammatory response in 10-week peritoneal lavage samples when compared to their tagged mature female counterparts, providing some evidence that mature female rainbow trout may have suppressed immune function when sexually mature. Externally, fish appeared to heal at similar rates regardless of the presence or absence of the transmitter, but the tag itself was prone to encapsulation and adhesion to the body wall and/or surgical site. This suggests that fish tagged with large intraperitoneal implants may not behave similarly to their wild counterparts. This research could aid in the development of improved telemetry tags that are more biocompatible, economical and better able to track fish behavior/movement.

Validating Star-Oddi heart rate and acceleration data storage tags for use in Atlantic salmon (Salmo salar)

“…The reason(s) for this prolonged recovery period is/are not known. However, these data are consistent with Hvas et al [43], and recent data suggest that the presence of tags inside the body cavity induces a long-term immune response [44]. This latter finding may provide an explanation for the lengthy period required for f H to achieve stable values.…”

PACAP Is Lethal to Flavobacterium psychrophilum Through Either Direct Membrane Permeabilization or Indirectly, by Priming the Immune Response in Rainbow Trout Macrophages

“…Flavobacterium psychrophilum strain 101 (FPG101) was grown as described previously by Semple et al (44) with minor adjustments. This bacterial isolate has been characterized as virulent in experimental trials by Jarau et al (52).…”

“…Despite concerted efforts to selectively breed for resistance to F. psychrophilum (33, 37–39) and multiple attempts to develop an effective vaccine [reviewed by Gomez et al (40), Makesh et al (41), and Hoare et al (42)], there is little information regarding the pathogenesis of the organism. Based on the data presented thus far, it appears that F. psychrophilum has an intricate relationship with the spleen and head kidney macrophages of rainbow trout (43, 44). As such, the spleen monocyte/macrophage-like cell line, RTS11 (45), would be an ideal model system for studying F. psychrophilum infections.…”

What are the relative risks of mortality and injury for fish during downstream passage at hydroelectric dams in temperate regions? A systematic review

“…Some tracking/marking techniques are more invasive than others, which could ultimately influence fish behaviour during downstream passage events. For example, surgically implanting an acoustic telemetry transmitter typically involves sedation and the implanted transmitter can produce an immune response, both of which may impair fish behaviour [68]. Conversely, PIT tags typically do not require sedation and are minimally invasive to implant in the fish.…”