Histology of dart tag insertion sites in the epaulette shark

• Published in: Journal of Fish Biology
• Main Authors: Heupel, MR, Bennett, MB
• Format: Article in Journal/Newspaper
• Language: English
• Published: ACADEMIC PRESS LTD 1997
• Subjects: Fisheries; Marine & Freshwater Biology; Epaulette Shark; Hemiscyllium Ocellatum; Dart Tag; Injury; Repair; Elasmobranch; Western North-atlantic; Great-barrier-reef; Abundance; Growth; 1104 Aquatic Science; 1105 Ecology; Evolution; Behavior and Systematics; North Atlantic
• Online Access: https://espace.library.uq.edu.au/view/UQ:57664

Samples of dermal and epidermal tissues of epaulette sharks Hemiscyllium ocellatum were examined histologically to assess damage caused by tagging. Tissues from around tag sites were removed at time intervals ranging from 100 min to 284 days post-tagging. These samples showed acute and chronic responses to tagging. Acute responses consisted of localized tissue breakdown and haemorrhaging, and occurred within the first few hours after tag insertion. At 10 h post-tagging, an intermediate response was apparent. This phase was characterized by further haemorrhaging and red and white blood cell movement into the wound area. The chronic response observed in the 10-284-day post-tagging samples was characterized by fibrous tissue formation to sequester the tag. This tissue presumably protects the adjacent musculature from further trauma produced by movement of the tag and provides a continuous barrier between the internal and external milieu. Tissue repair appeared to progress consistently in all specimens and no secondary infections at the tag site were seen. Tagging produced only localized tissue disruption and did not appear to be detrimental to the long term health of individual sharks. Our findings show that spaghetti style dart tagging is an acceptable method for marking individuals (40-75+ cm total length) of this species. (C) 1997 The Fisheries Society of the British Isles.