scholarly journals Seasonal aggregation of juvenile whale sharks (Rhincodon typus) at Christmas Island, Indian Ocean

Coral Reefs ◽  
2009 ◽  
Vol 28 (3) ◽  
pp. 577-577 ◽  
Author(s):  
J-P. A. Hobbs ◽  
A. J. Frisch ◽  
T. Hamanaka ◽  
C. A. McDonald ◽  
J. J. Gilligan ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Rhincodon Typus ◽  
Christmas Island ◽  
Whale Sharks

scholarly journals The ecological connectivity of whale shark aggregations in the Indian Ocean: a photo-identification approach

2016 ◽  
Vol 3 (11) ◽  
pp. 160455 ◽  
Author(s):  
Samantha Andrzejaczek ◽  
Jessica Meeuwig ◽  
David Rowat ◽  
Simon Pierce ◽  
Tim Davies ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Time Frame ◽  
Ocean Basin ◽  
Identification System ◽  
Whale Shark ◽  
Monte Carlo Simulation Study ◽  
Photo Identification ◽  
Christmas Island ◽  
Modelling Studies ◽  
Whale Sharks

Genetic and modelling studies suggest that seasonal aggregations of whale sharks ( Rhincodon typus ) at coastal sites in the tropics may be linked by migration. Here, we used photo-identification (photo-ID) data collected by both citizen scientists and researchers to assess the connectedness of five whale shark aggregation sites across the entire Indian Ocean at timescales of up to a decade. We used the semi-automated program I 3 S (Individual Interactive Identification System) to compare photographs of the unique natural marking patterns of individual whale sharks collected from aggregations at Mozambique, the Seychelles, the Maldives, Christmas Island (Australia) and Ningaloo Reef (Australia). From a total of 6519 photos, we found no evidence of connectivity of whale shark aggregations at ocean-basin scales within the time frame of the study and evidence for only limited connectivity at regional (hundreds to thousands of kilometres) scales. A male whale shark photographed in January 2010 at Mozambique was resighted eight months later in the Seychelles and was the only one of 1724 individuals in the database to be photographed at more than one site. On average, 35% of individuals were resighted at the same site in more than one year. A Monte Carlo simulation study showed that the power of this photo-ID approach to document patterns of emigration and immigration was strongly dependent on both the number of individuals identified in aggregations and the size of resident populations.

DNA evidence of whale sharks (Rhincodon typus) feeding on red crab (Gecarcoidea natalis) larvae at Christmas Island, Australia

2009 ◽  
Vol 60 (6) ◽  
pp. 607 ◽  
Author(s):  
M. G. Meekan ◽  
S. N. Jarman ◽  
C. McLean ◽  
M. B. Schultz
Keyword(s):  
Small Subunit ◽  
Whale Shark ◽  
Faecal Dna ◽  
Rhincodon Typus ◽  
Christmas Island ◽  
Crab Larvae ◽  
Pcr Products ◽  
Whale Sharks ◽  
Primer Sets ◽  
Gecarcoidea Natalis

Whale sharks (Rhincodon typus) are thought to aggregate in nearshore waters around Christmas Island (105°37′E, 10o29′S) to consume the marine larvae of the endemic red land crab (Gecarcoidea natalis). However, there have been no direct observations of sharks feeding on crab larvae. Whale shark faeces were analysed using genetic testing to confirm the presence of crab larvae in their diet. Primers were designed for amplifying two Gecarcoidea natalis mitochondrial small-subunit (mtSSU) rDNA regions. Gel electrophoresis of polymerase chain reaction (PCR) products amplified from whale shark faecal DNA produced bands of the expected size for G. natalis templates. Specificity of both primer sets for G. natalis mtSSU rDNA was expected to be high from comparisons with mtSSU rDNA regions from closely related crabs and we confirmed their specificity empirically. The amplification of fragments from faecal DNA of the same size as those produced from G. natalis DNA indicates that the whale shark had been feeding on G. natalis and that enough of the crab DNA survived digestion to be detected by these PCRs. Our study provides further evidence that aggregations of whale sharks in coastal waters occur in response to ephemeral but predictable increases in planktonic prey.

New records of neonatal and juvenile whale sharks (Rhincodon typus) from the Indian Ocean

2007 ◽  
Vol 82 (3) ◽  
pp. 215-219 ◽  
Author(s):  
D. Rowat ◽  
M. A. Gore ◽  
B. B. Baloch ◽  
Z. Islam ◽  
E. Ahmad ◽  
...  
Keyword(s):  
Indian Ocean ◽  
New Records ◽  
Rhincodon Typus ◽  
Whale Sharks ◽  
The Indian Ocean

scholarly journals Regional movements of satellite‐tagged whale sharks Rhincodon typus in the Gulf of Aden

2021 ◽  
Author(s):  
Samantha Andrzejaczek ◽  
Michel Vély ◽  
Daniel Jouannet ◽  
David Rowat ◽  
Sabrina Fossette
Keyword(s):  
Gulf Of Aden ◽  
Rhincodon Typus ◽  
Whale Sharks

scholarly journals Diet of whale sharks Rhincodon typus inferred from stomach content and signature fatty acid analyses

2013 ◽  
Vol 493 ◽  
pp. 219-235 ◽  
Author(s):  
CA Rohner ◽  
LIE Couturier ◽  
AJ Richardson ◽  
SJ Pierce ◽  
CEM Prebble ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Stomach Content ◽  
Rhincodon Typus ◽  
Whale Sharks

scholarly journals Spatial and temporal patterns of nature-based tourism interactions with whale sharks (Rhincodon typus) at Ningaloo Reef, Western Australia

2014 ◽  
Vol 148 ◽  
pp. 109-119 ◽  
Author(s):  
Douglas J. Anderson ◽  
Halina T. Kobryn ◽  
Brad M. Norman ◽  
Lars Bejder ◽  
Julian A. Tyne ◽  
...  
Keyword(s):  
Western Australia ◽  
Temporal Patterns ◽  
Spatial And Temporal Patterns ◽  
Rhincodon Typus ◽  
Ningaloo Reef ◽  
Whale Sharks

scholarly journals Sizing and scarring of whale shark (Rhincodon typus Smith, 1828) in the Cenderawasih Bay National Park

2021 ◽  
Vol 21 (3) ◽  
pp. 199-213
Author(s):  
Yusup A Jentewo ◽  
Roni Bawole ◽  
Tresia S Tururaja ◽  
Mudjirahayu Mudjirahayu ◽  
Zeth Parinding ◽  
...  
Keyword(s):  
National Park ◽  
The Body ◽  
Whale Shark ◽  
Gill Slit ◽  
Rhincodon Typus ◽  
Photo Identification ◽  
Dorsal Fin ◽  
Total Length ◽  
Whale Sharks ◽  
Photo Collection

This study aims to determine the total length and scar condition of the body of whale sharks (Rhincodon typus) in Cendrawasih Bay National Park (TNTC), Papua-Indonesia. Photo-identification was used to identify individuals of the whale shark R. typus based on spot patterns behind the last gill slit of each individual. Photo-identification was also used to determine the scar of the whale shark. The total length of whale sharks were estimated based on the length of a snorkeller (assumed to be 1.6 m) swimming alongside the whale shark. We identified 21 individuals of R. typus. Of these 21 individuals, 14 were new sightings and seven were re-sightings that have been recorded in the previous photo collection database. R. typus ranged in size from 2 to 5 m total length (average 3.78 m, ±0,86, N= 21). Based on their size, all individuals of whale shark were categorized as juvenile. 52% of R. typus identified had scars and 38 % were not and 10% were unknown. The majority of whale sharks had amputation (12 individuals) and abrasion (7 individuals) scars. Scars occurred most often on the caudal fin and dorsal fin, five and four individuals respectively. This information is useful for understanding potential threats and designing better management programmes for R. typus conservation in TNTC.

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