{"title":"一头胸鳍明显畸形的白鲨(Carcharodon carcharias)在南加州海岸附近被发现","authors":"Phil Sternes, Patrick L. Jambura","doi":"10.3160/0038-3872-120.2.59","DOIUrl":null,"url":null,"abstract":"It is well known that sharks frequently suffer injuries throughout their life due to various natural causes (Pratt and Carrier 2001; Chin et al. 2015; Becerril-García et al. 2020), including human interactions (Lester et al. 2020). Although sharks show both remarkable resilience and wound-healing capabilities (Reif 1978; Womersely et al. 2021) to minor injuries such as lacerations, some injuries are so substantial that they remain present for the rest of the individual’s life (Mumby 2019; Womersely et al. 2021). For example, in 2014 a grey reef shark, Carcharhinus amblyrhynchos (Bleeker, 1856), was observed to be missing its entire first dorsal fin at a reef near Palau (Mumby 2019). Remarkably, the same individual was seen again four years later near the original study site, indicating that it had survived with the permanent injury (Mumby 2019). It is known that the dorsal fin either aids in stability or in generating thrust depending on its size and position on the body (LinghamSoliar 2005; Maia et al. 2017). However, it is unknown what functional consequences a shark may suffer when missing a dorsal fin (Harris 1936). Nevertheless, it was concluded that this grey shark most likely used a variety of feeding tactics to capture prey and survive to compensate the loss of its dorsal fin (Mumby 2019). Whereas grey reef sharks are moderately sized mesopredators (Roff et al. 2016), it is unknown how such injuries may impact the behavior and survival of large predatory sharks such as the white shark, Carcharodon carcharias (Linnaeus, 1758). Here, we present evidence of a white shark with a highly deformed pectoral fin that has been filmed twice over a five month period. Additionally, we discuss the possible functional consequences the white shark may have suffered and how this shark has most likely modified its behavior and survived during this time span. On the morning of 27 August 2020, a juvenile white shark of unknown sex (C. Gauna pers. comm.) with a deformed left pectoral fin was observed via drone just off the coast of Santa Barbara, California, USA (Fig. 1a). The pectoral fin was intact but was bent up at nearly a 90° angle practically flush against the body. The shark appeared to be swimming in the upright position without any indication of it swimming on a rolled axis despite its pectoral fin deformity (Fig. 1a and Supporting Information Video S1). However, the shark appears to be putting forth increased effort just to swim in an irregular motion (non-thunniform) most likely due to its pectoral fin deformity (Supporting Information Video S1). In addition, it is unknown if this was a birth deformity or if the deformity was sustained later in life by some other cause (i.e., natural or human related). On the evening of 17 January 2021, almost five months after the first observation, the same individual was filmed in the same area again (Fig. 1b).","PeriodicalId":90803,"journal":{"name":"Bulletin (Southern California Academy of Sciences)","volume":"30 1","pages":"59 - 63"},"PeriodicalIF":0.0000,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Sightings of a White Shark (Carcharodon carcharias) with a Significantly Deformed Pectoral Fin off the coast of Southern California\",\"authors\":\"Phil Sternes, Patrick L. Jambura\",\"doi\":\"10.3160/0038-3872-120.2.59\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"It is well known that sharks frequently suffer injuries throughout their life due to various natural causes (Pratt and Carrier 2001; Chin et al. 2015; Becerril-García et al. 2020), including human interactions (Lester et al. 2020). Although sharks show both remarkable resilience and wound-healing capabilities (Reif 1978; Womersely et al. 2021) to minor injuries such as lacerations, some injuries are so substantial that they remain present for the rest of the individual’s life (Mumby 2019; Womersely et al. 2021). For example, in 2014 a grey reef shark, Carcharhinus amblyrhynchos (Bleeker, 1856), was observed to be missing its entire first dorsal fin at a reef near Palau (Mumby 2019). Remarkably, the same individual was seen again four years later near the original study site, indicating that it had survived with the permanent injury (Mumby 2019). It is known that the dorsal fin either aids in stability or in generating thrust depending on its size and position on the body (LinghamSoliar 2005; Maia et al. 2017). However, it is unknown what functional consequences a shark may suffer when missing a dorsal fin (Harris 1936). Nevertheless, it was concluded that this grey shark most likely used a variety of feeding tactics to capture prey and survive to compensate the loss of its dorsal fin (Mumby 2019). Whereas grey reef sharks are moderately sized mesopredators (Roff et al. 2016), it is unknown how such injuries may impact the behavior and survival of large predatory sharks such as the white shark, Carcharodon carcharias (Linnaeus, 1758). Here, we present evidence of a white shark with a highly deformed pectoral fin that has been filmed twice over a five month period. Additionally, we discuss the possible functional consequences the white shark may have suffered and how this shark has most likely modified its behavior and survived during this time span. On the morning of 27 August 2020, a juvenile white shark of unknown sex (C. Gauna pers. comm.) with a deformed left pectoral fin was observed via drone just off the coast of Santa Barbara, California, USA (Fig. 1a). The pectoral fin was intact but was bent up at nearly a 90° angle practically flush against the body. The shark appeared to be swimming in the upright position without any indication of it swimming on a rolled axis despite its pectoral fin deformity (Fig. 1a and Supporting Information Video S1). However, the shark appears to be putting forth increased effort just to swim in an irregular motion (non-thunniform) most likely due to its pectoral fin deformity (Supporting Information Video S1). In addition, it is unknown if this was a birth deformity or if the deformity was sustained later in life by some other cause (i.e., natural or human related). On the evening of 17 January 2021, almost five months after the first observation, the same individual was filmed in the same area again (Fig. 1b).\",\"PeriodicalId\":90803,\"journal\":{\"name\":\"Bulletin (Southern California Academy of Sciences)\",\"volume\":\"30 1\",\"pages\":\"59 - 63\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2021-10-12\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Bulletin (Southern California Academy of Sciences)\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.3160/0038-3872-120.2.59\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bulletin (Southern California Academy of Sciences)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3160/0038-3872-120.2.59","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
众所周知,鲨鱼在其一生中经常因各种自然原因而受伤(Pratt and Carrier 2001;Chin et al. 2015;Becerril-García et al. 2020),包括人类互动(Lester et al. 2020)。尽管鲨鱼表现出非凡的恢复力和伤口愈合能力(Reif 1978;Womersely et al. 2021)到轻微的伤害,如撕裂伤,有些伤害非常严重,以至于在个人的余生中仍然存在(Mumby 2019;Womersely et al. 2021)。例如,2014年,在帕劳附近的一个珊瑚礁上,一只灰色礁鲨Carcharhinus amblyrhynchos (Bleeker, 1856)被观察到失去了整个第一个背鳍(Mumby 2019)。值得注意的是,四年后,在最初的研究地点附近再次看到了同一个人,这表明它在永久性损伤下幸存了下来(Mumby 2019)。众所周知,背鳍要么有助于稳定,要么产生推力,这取决于它在身体上的大小和位置(LinghamSoliar 2005;Maia et al. 2017)。然而,目前尚不清楚鲨鱼在失去背鳍时可能遭受的功能后果(Harris 1936)。然而,得出的结论是,这种灰鲨最有可能使用各种喂养策略来捕获猎物并生存下来,以弥补背鳍的损失(Mumby 2019)。灰礁鲨是中等大小的中掠食性鲨鱼(Roff et al. 2016),目前尚不清楚这种伤害如何影响白鲨Carcharodon carcharias等大型掠食性鲨鱼的行为和生存(Linnaeus, 1758)。在这里,我们提供了一条胸鳍高度变形的白鲨的证据,它在五个月内被拍摄了两次。此外,我们还讨论了白鲨可能遭受的功能后果,以及这条鲨鱼如何最有可能改变其行为并在这段时间内存活下来。2020年8月27日上午,一只性别不明的幼白鲨(C. Gauna pers.)在美国加利福尼亚州圣巴巴拉海岸附近,通过无人机观察到一条左胸鳍变形的鲨鱼(图1a)。胸鳍完好无损,但弯曲成近90°角,几乎与身体齐平。尽管胸鳍畸形,但鲨鱼似乎是直立游泳,没有任何迹象表明它是沿滚动轴游泳的(图1a和支持信息视频S1)。然而,鲨鱼似乎只是为了不规则地游动而付出了更大的努力,这很可能是由于它的胸鳍畸形(支持信息视频S1)。此外,尚不清楚这是先天畸形,还是由于其他原因(即自然或人为原因)导致的畸形。2021年1月17日晚,在第一次观察后近5个月,在同一区域再次拍摄到同一个体(图1b)。
Sightings of a White Shark (Carcharodon carcharias) with a Significantly Deformed Pectoral Fin off the coast of Southern California
It is well known that sharks frequently suffer injuries throughout their life due to various natural causes (Pratt and Carrier 2001; Chin et al. 2015; Becerril-García et al. 2020), including human interactions (Lester et al. 2020). Although sharks show both remarkable resilience and wound-healing capabilities (Reif 1978; Womersely et al. 2021) to minor injuries such as lacerations, some injuries are so substantial that they remain present for the rest of the individual’s life (Mumby 2019; Womersely et al. 2021). For example, in 2014 a grey reef shark, Carcharhinus amblyrhynchos (Bleeker, 1856), was observed to be missing its entire first dorsal fin at a reef near Palau (Mumby 2019). Remarkably, the same individual was seen again four years later near the original study site, indicating that it had survived with the permanent injury (Mumby 2019). It is known that the dorsal fin either aids in stability or in generating thrust depending on its size and position on the body (LinghamSoliar 2005; Maia et al. 2017). However, it is unknown what functional consequences a shark may suffer when missing a dorsal fin (Harris 1936). Nevertheless, it was concluded that this grey shark most likely used a variety of feeding tactics to capture prey and survive to compensate the loss of its dorsal fin (Mumby 2019). Whereas grey reef sharks are moderately sized mesopredators (Roff et al. 2016), it is unknown how such injuries may impact the behavior and survival of large predatory sharks such as the white shark, Carcharodon carcharias (Linnaeus, 1758). Here, we present evidence of a white shark with a highly deformed pectoral fin that has been filmed twice over a five month period. Additionally, we discuss the possible functional consequences the white shark may have suffered and how this shark has most likely modified its behavior and survived during this time span. On the morning of 27 August 2020, a juvenile white shark of unknown sex (C. Gauna pers. comm.) with a deformed left pectoral fin was observed via drone just off the coast of Santa Barbara, California, USA (Fig. 1a). The pectoral fin was intact but was bent up at nearly a 90° angle practically flush against the body. The shark appeared to be swimming in the upright position without any indication of it swimming on a rolled axis despite its pectoral fin deformity (Fig. 1a and Supporting Information Video S1). However, the shark appears to be putting forth increased effort just to swim in an irregular motion (non-thunniform) most likely due to its pectoral fin deformity (Supporting Information Video S1). In addition, it is unknown if this was a birth deformity or if the deformity was sustained later in life by some other cause (i.e., natural or human related). On the evening of 17 January 2021, almost five months after the first observation, the same individual was filmed in the same area again (Fig. 1b).