Factors Affecting Survival of Cobia, Rachycentron canadum, during Simulated Transport

Abstract

Interest in cobia, Rachycentron canadum, culture has shown significant growth in recent years, but few hatcheries are available to support this developing industry. To facilitate the transport of cobia between facilities, four 24‐h experiments were conducted to examine the effects of density, temperature, and actual versus simulated transport on juvenile cobia (1.5–3.0 g) survival. Mortality during actual transport at fish densities of 5, 10, and 15 kg/m3 (2.9 ± 0.6, 2.9 ± 1.8, and 6.3 ± 0.8%, respectively) did not differ by treatment but was significantly higher than that during simulated transport at each density (0%). No differences in mortality were found following simulated shipping at 19, 21, and 25 C at 15 kg/m3. Significantly greater mortality occurred when juveniles were packed at 25 kg/m3 (10.4 ± 0.7%) than at 20 kg/m3 (1.9 ± 1.6%) and 15 kg/m3 (0.1 ± 0.1%). Recovery following simulated and actual shipping was high in all treatment groups. Under the conditions examined, results indicate that transport density should not exceed 20 kg/m3.

Culture of cobia Rachycentron canadum (L) in near-shore cages off the Brazilian coast

“…Temperature and salinity were maintained at 20 1C and 32 ppt respectively. Fish density during transport was 2 g L À 1 , below the limit of 20 g L À 1 recommended by Colburn, Walker, Berlinsky and Nardi (2008).…”

Effects of stocking density and water conditioners on yolk-sac larvae of two marine finfish during simulated air transport

“…Water conditioners like the one used in this study (i.e. Trizma â ) have been used safely and effectively to buffer against changes in pH for both fresh and salt water species in concentrations as high as 3.0 g L À1 (Piper, McElwain, Orme, McCraren, Fowler & Leonard 1982;Turner & Bower 1982;FAO 1986;Colburn et al 2008). In both CYT and WSB trials, pH levels dropped below 8.0 when the buffer concentrations were below 1.5 g L À1 and when stocking densities were increased above 6000 larvae L À1 .…”

“…; Estudillo & Duray ), cobia (juvenile; Rachycentron canadum ; Colburn et al . ) and yellowfin tuna (yolk‐sac larvae; Thunnus albacares ; Zink et al . ).…”

“…Maintaining high dissolved oxygen concentration, reducing toxic ammonia, and buffering against pH shifts are typical water quality related goals for transport (Turner & Bower 1982;FAO 1986;Zink, Benetti, Douillet, Margulies & Scholey 2011). To maintain acceptable water quality parameters during shipment of juvenile fish and shrimp, many techniques have been developed, including starving the animals before shipment (Nemoto 1957), lowering temperature of the shipping water (Teo & Chen 1993), adding anaesthetics to the shipment water (Teo, Chen & Lee 1989;Guo, Teo & Chen 1995), and adding water conditioners (Turner & Bower 1982;FAO 1986;Colburn, Walker, Berlinsky & Nardi 2008). However, similar protocols for early life stages of marine finfish have not yet been fully developed and published.…”

The use of feed and water additives for live fish transport

“…Stress Coat â (API Aquarium Pharmaceuticals Inc., n.d.) is a commercially available water conditioner which is recommended for addition to water during transport and to tank water during other potentially stressful procedures. Several studies have used Stress Coat â in husbandry procedures (Earley et al 2006;Colburn et al 2008;Harnish et al 2011;Wong et al 2015), however, much of the information on Stress Coat â is not in the peer-reviewed literature. Snellgrove et al (2007) found that water cortisol levels excreted by goldfish exposed to Stress Coat â were lower following netting compared with goldfish netted with no Stress Coat â exposure.…”