Retention of fin clips and fin and operculum punch marks in rainbow trout

Fin clips(complete fin removal)or punch marks(stamping of a hole)in fins or operculum are quick and inexpensive methods to identify individuals or groups of fish.This study evaluated the retention of 6 mm diameter punch marks on the operculum,caudal(upper and lower lobes),dorsal,pelvic,and anal fins,and fin clips on adipose,pectoral,pelvic,dorsal and anal fins of rainbow trout Oncorhynchus mykiss for 279 days.Growth and survival were not significantly different among fish with the different mark types or locations.At the end of the experiment,100%of adipose clips,97%of pectoral and anal fin clips,and 93%of dorsal clips and pelvic fin clips were retained.Retention of punch marks was 57%and 50%for the lower and upper caudal fin lobe locations respectively,23%for the dorsal fin,and 3%for the operculum.No pelvic or anal fin punch marks were identified at the end of the trial.Significant differences in retention among the treatment groups did not occur until 125 days post marking,after which all fin clip treatments had significantly greater retention than pelvic and dorsal punch marks.Beyond 244 days,fin clips outperformed all punch mark locations.

A comparison of cyanoacrylate to sutures for wound closure following acoustic transmitter insertion in rainbow trout

Tag retention,wound healing,wound closure,and tagged fish survival are critically important after surgical implantation of acoustic transmitters in fish.This study compared the use of sutures to cyanoacrylate adhesives and bandages for post-surgery wound closure.Adult rainbow trout Oncorhynchus mykiss were assigned to one of seven treatments:a control group where fish were only handled,two suture groups(tagged with dummy acoustic transmitters or non-tagged),and four cyanoacrylate adhesive groups(non-tagged,tagged with adipose fin applied as a biological bandage,tagged with anal fin applied,and non-tagged with water-proof bandage).Tag retention was significantly improved in adhesive with anal fin(89%)and tagged suture(78%)treatments when compared to only 11%tag retention in the adhesive with adipose fin treatment.Wound redness severity increased over the 14 weeks of the study in the tagged and sutured fish,and in those receiving the waterproof bandage.Wound redness severity was also significantly higher in the waterproof bandage and tagged and sutured treatments than both tagged adhesive treatments at the end of the study.Wound gape was significantly more severe in the adhesive with adipose treatment than in the control,suture,tagged suture,and adhesive treatments,but no significant differences were observed between the adhesive with adipose treatment and the adhesive with anal fin or bandage treatments.Wound gape never completely closed in the adhesive with adipose group,while both the tagged suture treatment and tagged adhesive with anal treatment wounds completely closed between four-and six-weeks post-surgery.The results of this study indicate that cyanoacrylate adhesive used in conjunction with anal fin tissue is a suitable post-surgical treatment.