The Effect of Capture and Handling Stress on Plasma Steroid Levels and Gonadal Condition in Wild and Farmed Snapper Pagrus auratus (Sparidae)

The present study investigated the stock structure of snapper (Pagrus auratus) in South Australia, and the extent to which this is influenced by adult movement. Fish from the 9+ age class were sampled from six different regions, encompassing >2000 km of coastline and different habitat types. The chemistry of transverse sections of otoliths was sampled using laser ablation inductively coupled plasma-mass spectrometry, providing elemental profiles that were related to age for the first nine years of the fish’s lives. The age-related annual averages for both 88Sr and 138Ba differed significantly between regions. They were, however, similar for the first three years, then diverged considerably between the ages of three to five years, and then remained consistently different through to the age of nine years. This suggests that all fish, regardless of where captured, originated from only one or two nursery areas, but dispersed throughout the different regions between the ages of three to five years, before becoming resident to their new regions of occupancy. Thus, this population of snapper represents a single, large, stock where the individuals have a common origin, but through age-related emigration ultimately disperse and supplement the low abundance populations in regional State waters.

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The aquaculture of Acipenseriformes. Part 6. Northern and South America

Rybovodstvo i rybnoe hozjajstvo (Fish Breeding and Fisheries) ◽

10.33920/sel-09-2010-07 ◽

2020 ◽

pp. 68-79

Author(s):

I. V. Trenkler

Keyword(s):

South America ◽

Ictalurus Punctatus ◽

Macrobrachium Rosenbergii ◽

High Rate ◽

White Sturgeon ◽

Low Oxygen ◽

Handling Stress ◽

Poor Tolerance ◽

Important Object ◽

The University

The history and contemporary state of global aquaculture of sturgeons and paddlefish are reviewed. The paddlefish Polyodon spathula became first object of cultivation of Acipenseriformes in USA. The paddlefish has high rate of growth in ponds using natural feeds, mature females can produce about 15% of their body weight in roe similar to eggs of star sturgeon Acipenser stellatus. Some liabilities include juveniles vulnerable to bird predation, poor tolerance to high densities, low oxygen and handling stress, waiting period of at least 7 years before females produce eggs. The paddlefish farming is carried out mainly in Kentucky, Indiana, Missouri and Alabama in polyculture with canal catfish Ictalurus punctatus or freshwater shrimp Macrobrachium rosenbergii. The most important object of North-American sturgeon breeding is white sturgeon Acipenser transmontanus, the biggest and fast-growing species of Acipenser genera. The largest commercial sturgeon farms are located in California, Idaho and Florida. A research program on biotechnology of white sturgeon farming has been initiated by the University of California at Davis in December 1979. The first successful artificial propagation of white sturgeon from Sacramento River was carried out in 1980, the first hatchery females matured in 1994. The hatchery progeny of Snake River white sturgeon was received in 1988, the first females matured in 2000. The first caviar was processed only after maturation of second generation. In Florida and North Carolina farmers used for cultivation small number of Russian sturgeon A. gueldenstaedti, Siberian sturgeon A. baeri, sterlet A. ruthenus, beluga Huso huso and star sturgeon A. stellatus. The total annual volume of sturgeon farming in USA was equal to 1285 tons (1166 MT). In Canada the only object of sturgeon farming is white sturgeon with annual production near 2 tons of caviar. In South America Uruguay has developed sturgeon culture with one large farm created in 1994 using help of Russian specialists.

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