A dataset containing life history information for 475 common blacktip sharks, Carcharhinus limbatus, collected from south-east Queensland and northern New South Wales, Australia, between 2004 and 2013. These are the data analysed by Harry et al. (2019), including the corrections made in that study.
Format
A data frame with 475 rows and 24 variables:
- source
Data source:
"QLD 2004-2007", Moreton Bay survey;"QLD 2007", neonates purchased from a Moreton Bay commercial fisher;"NSW 2008-2010"and"NSW 2013", observer surveys of the New South Wales Ocean Trap and Line Fishery- date
Date collected
- month
Month, integer form
- year
Calendar year
- tag
Identification number
- FL
Fork length (cm)
- STL
Stretched total length (cm), measured with the upper caudal lobe depressed in line with the body axis
- PCL
Pre-caudal length (cm)
- wgt
Weight (kg)
- sex
2 level factor
- umb_scar
Umbilical scar open? Yes, no or partially
- neonate
Known age-zero individual,
TRUEwhere the umbilical scar was open or partially healed- clasp_length
Outer length of male claspers (mm)
- clasp_calc
Were claspers calcified? Yes, no or partially
- uter_stage
Macroscopic staging of female uterus, 1 to 6 (recorded as A to F in the original data)
- maturity_stage
Binary maturity stage: 0, immature; 1, mature
- maternity_stage
Binary female maternity stage: 0, non-maternal; 1, maternal
- emb
Number of embryos
- embTL
Mean total length of embryos (mm)
- male_emb
Number of male embryos
- female_emb
Number of female embryos
- reader1
Age from the first reader, adjusted for date of birth
- reader2
Age from the second reader, adjusted for date of birth
- age_agree
Consensus age estimate, adjusted for date of birth
Details
The data combine four sources that used different fishing gears and sampled different parts of the population. Sharks from Moreton Bay, Queensland, were mostly neonates and small juveniles, sampled by fishery-independent methods and by a commercial gillnet fisher. Sharks from New South Wales were mostly larger than 150 cm and were caught on demersal setlines by the Ocean Trap and Line Fishery. Vertebrae were collected only from the 2008 to 2010 New South Wales survey, and umbilical scars were recorded only in Queensland. Species identity in the 2008 to 2010 survey was determined genetically, and individuals of hybrid ancestry with C. tilstoni are included, as in the original study.
Ages are counts of growth zone pairs on sectioned vertebrae, read
independently by two readers, plus the fraction of a year between an
assumed birth date of 1 November and the start of the month of capture.
The same fraction is added to both readings and the consensus age, so they
can be passed directly to growth().
References
Harry, A.V., Butcher, P.A., Macbeth, W.G., Morgan, J.A.T., Taylor, S.M. and Geraghty, P.T. (2019) Life history of the common blacktip shark, Carcharhinus limbatus, from central eastern Australia and comparative demography of a cryptic shark complex. Marine and Freshwater Research 70(6), 834-848. doi:10.1071/MF18141