Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Jan 16;9(1):coaa120.
doi: 10.1093/conphys/coaa120. eCollection 2021.

Wound-healing capabilities of whale sharks (Rhincodon typus) and implications for conservation management

Freya Womersley  1   2   3 , James Hancock  4 , Cameron T Perry  4 , David Rowat  3
Affiliations

Wound-healing capabilities of whale sharks (Rhincodon typus) and implications for conservation management

Freya Womersley et al. Conserv Physiol. .

Abstract

Wound healing is important for marine taxa such as elasmobranchs, which can incur a range of natural and anthropogenic wounds throughout their life history. There is evidence that this group shows a high capacity for external wound healing. However, anthropogenic wounds may become more frequent due to increasing commercial and recreational marine activities. Whale sharks are particularly at risk of attaining injuries given their use of surface waters and wildlife tourism interest. There is limited understanding as to how whale sharks recover from injuries, and often insights are confined to singular opportunistic observations. The present study makes use of a unique and valuable photographic data source from two whale shark aggregation sites in the Indian Ocean. Successional injury-healing progression cases were reviewed to investigate the characteristics of injuries and quantify a coarse healing timeframe. Wounds were measured over time using an image standardization method. This work shows that by Day 25 major injury surface area decreased by an average of 56% and the most rapid healing case showed a surface area reduction of 50% in 4 days. All wounds reached a point of 90% surface area closure by Day 35. There were differences in healing rate based on wound type, with lacerations and abrasions taking 50 and 22 days to reach 90% healing, respectively. This study provides baseline information for wound healing in whale sharks and the methods proposed could act as a foundation for future research. Use of a detailed classification system, as presented here, may also assist in ocean scale injury comparisons between research groups and aid reliable descriptive data. Such findings can contribute to discussions regarding appropriate management in aggregation areas with an aim to reduce the likelihood of injuries, such as those resulting from vessel collisions, in these regions or during movements between coastal waters.

Keywords: Healing rate; anthropogenic activities; conservation management; whale shark; wildlife injuries; wound healing.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Examples of injuries (⇒) of varying type, location and severity, attributed to both natural and anthropogenic sources, portraying severity within four type groups. Images (1A)–(4A) portray ‘major’ wounds which were determined based on quantifiable characteristics (Table 1) and images (1B)–(4B) portray ‘minor’ wounds.
Figure 2
Figure 2
Example of methodology implemented to quantify wound change over time. The rectangle and freehand tools in FIJI by ImageJ were used to measure wound surface area and perimeter in pixels relative to the selected scale marking.
Figure 3
Figure 3
Examples of open injuries to the pectoral (A) and first dorsal (B) fins with a notable pallid epidermis surrounding the wound site and fibrous tissue present at the open wound site.
Figure 4
Figure 4
Example of the epidermis folding inward around a major laceration perimeter 16 days (B) after the wound was initially sighted (A) in December 2016.
Figure 5
Figure 5
Example of appendage regeneration. In 2006 (A,C) the individual is sighted with the tip of the first dorsal fin missing. Approximately 5 years later in 2011 (B,D) tissue appears to have regenerated to fill the previously severed area and reform the natural curved shape of the first dorsal fin.
Figure 6
Figure 6
Example of white spot marking pigmentation returning to a previously wounded area over the course of ~ 5 months. Markings visible in (E) were not present on first sighting (A) where the pigmented outer skin layer had been removed.
Figure 7
Figure 7
Example of an individual (WS198) which was sighted with a series of open vessel-induced lacerations to the right flank on 24 June 2015 (A). Less than 1 month later (B) the wounds showed signs of extensive healing with considerably less sub-dermal tissue visible and after approximately 6 months (C) the injury was classified as fully healed with the pigmented epidermal layers covering all tissues- In the years following (D and E) the scar showed little further change other than mild pigmentation alterations.
Figure 8
Figure 8
Temporal evolution (days since initial wound sighting) of wound healing showing total surface area reduction (%) of four distinct vessel-related injuries inflicted on WS198 over a three-year period.
Figure 9
Figure 9
Temporal evolution (days since initial wound sighting) of wound healing showing total surface area reduction (%). Best fit exponential model is shown (blue line) where the x intercept equals 34.84 days when 90% healing is reached (red dotted line).
Figure 10
Figure 10
Temporal evolution (days since initial wound sighting) of wound healing showing (A) total surface area reduction (%) for lacerations (teal) and abrasions (orange) where x intercepts are 50.17 (laceration) and 22.13 (abrasion) days when 90% healing is reached (dotted line) and (B) total perimeter reduction for lacerations (teal) and abrasions (orange) where x intercepts are 69.22 (laceration) and 34.82 (abrasion) days when 90% healing is reached (dotted line).
Figure 11
Figure 11
Temporal evolution (days since initial wound sighting) of wound healing showing rate of (A) surface area change between sightings (%) on a given day for lacerations (teal) and abrasions (orange) where critical x intercepts are 12.85 (laceration) (P < 0.001***) and 40.33 (abrasion) (P < 0.05*) days (dotted line) and (B) perimeter change between sightings on a given day for lacerations (teal) and abrasions (orange) where critical x intercepts are 38.66 (laceration) (P < 0.01**) and 42.25 (abrasion) (P < 0.05*) days (dotted line).
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

  • Global collision-risk hotspots of marine traffic and the world's largest fish, the whale shark.
    Womersley FC, Humphries NE, Queiroz N, Vedor M, da Costa I, Furtado M, Tyminski JP, Abrantes K, Araujo G, Bach SS, Barnett A, Berumen ML, Bessudo Lion S, Braun CD, Clingham E, Cochran JEM, de la Parra R, Diamant S, Dove ADM, Dudgeon CL, Erdmann MV, Espinoza E, Fitzpatrick R, Cano JG, Green JR, Guzman HM, Hardenstine R, Hasan A, Hazin FHV, Hearn AR, Hueter RE, Jaidah MY, Labaja J, Ladino F, Macena BCL, Morris JJ Jr, Norman BM, Peñaherrera-Palma C, Pierce SJ, Quintero LM, Ramírez-Macías D, Reynolds SD, Richardson AJ, Robinson DP, Rohner CA, Rowat DRL, Sheaves M, Shivji MS, Sianipar AB, Skomal GB, Soler G, Syakurachman I, Thorrold SR, Webb DH, Wetherbee BM, White TD, Clavelle T, Kroodsma DA, Thums M, Ferreira LC, Meekan MG, Arrowsmith LM, Lester EK, Meyers MM, Peel LR, Sequeira AMM, Eguíluz VM, Duarte CM, Sims DW. Womersley FC, et al. Proc Natl Acad Sci U S A. 2022 May 17;119(20):e2117440119. doi: 10.1073/pnas.2117440119. Epub 2022 May 9. Proc Natl Acad Sci U S A. 2022. PMID: 35533277 Free PMC article.
  • Pathological study of a traumatic anthropogenic injury in the skeleton of a spiny butterfly ray (Gymnura altavela).
    Montero-Hernández G, Caballero MJ, Curros-Moreno Á, Suárez-Santana CM, Rivero MA, Caballero-Hernández L, Encinoso M, Fernández A, Castro-Alonso A. Montero-Hernández G, et al. Front Vet Sci. 2024 Oct 24;11:1452659. doi: 10.3389/fvets.2024.1452659. eCollection 2024. Front Vet Sci. 2024. PMID: 39512913 Free PMC article.
  • Case report: Management and long-term ophthalmic sequelae of monogenean ocular infestation in cownose rays (Rhinoptera bonasus).
    Beatty A, Gemensky-Metzler A, Newbold G, Aplasca AC, Seeley KE. Beatty A, et al. Front Vet Sci. 2024 Jun 19;11:1401141. doi: 10.3389/fvets.2024.1401141. eCollection 2024. Front Vet Sci. 2024. PMID: 38966566 Free PMC article.
  • The salamander blastema within the broader context of metazoan regeneration.
    Tajer B, Savage AM, Whited JL. Tajer B, et al. Front Cell Dev Biol. 2023 Aug 11;11:1206157. doi: 10.3389/fcell.2023.1206157. eCollection 2023. Front Cell Dev Biol. 2023. PMID: 37635872 Free PMC article. Review.
  • Elasmobranch microbiomes: emerging patterns and implications for host health and ecology.
    Perry CT, Pratte ZA, Clavere-Graciette A, Ritchie KB, Hueter RE, Newton AL, Fischer GC, Dinsdale EA, Doane MP, Wilkinson KA, Bassos-Hull K, Lyons K, Dove ADM, Hoopes LA, Stewart FJ. Perry CT, et al. Anim Microbiome. 2021 Sep 15;3(1):61. doi: 10.1186/s42523-021-00121-4. Anim Microbiome. 2021. PMID: 34526135 Free PMC article. Review.
See all "Cited by" articles

References

    1. Anderson CD, Roberts RJ (1975) A comparison of the effects of temperature on wound healing in a tropical and a temperate teleost. J Fish Biol 7: 173–182.
    1. Araujo G, Lucey A, Labaja J, So CL, Snow S, Ponzo A (2014) Population structure and residency patterns of whale sharks, Rhincodon typus, at a provisioning site in Cebu, Philippines. PeerJ 2: e543. - PMC - PubMed
    1. Aubrey CW, Snelson FF Jr (2007) Early life history of the spinner shark in a Florida nursery In CT McCandless, NE Kohler, HL Pratt Jr, eds, Shark Nursery Grounds of the Gulf of Mexico and the East Coast Waters of the United States. American Fisheries Society, Symposium 50, Bethesda, MD, pp. 175–179.
    1. Bansemer CS, Bennett MB (2010) Retained fishing gear and associated injuries in the east Australian grey nurse sharks (Carcharias taurus): implications for population recovery. Mar Freshwater Res 61: 97–103.
    1. Bates D, Mächler B, Bolker B, Walker S (2014) Fitting linear mixed-effects models using lme4. J Stat Softw 67: 1–48.

LinkOut - more resources