Effects of salinity on eggs, larvae, and juveniles of blacknose silversides from Lake Chapala, Mexico

Citation

Martinez-Palacios CA, Salgado-Garcia RL, Racotta IS & Ross L (2008) Effects of salinity on eggs, larvae, and juveniles of blacknose silversides from Lake Chapala, Mexico. North American Journal of Aquaculture, 70 (1), pp. 12-19. https://doi.org/10.1577/A06-026.1

Abstract
The salinity tolerance of eggs, larvae, and juveniles of blacknose silverside Chirostoma promelas was investigated with the objective of optimizing hatchery practice. A high proportion (>90%) of eggs became eyed in all salinities. Eggs exposed to an instantaneous change of salinity hatched best at 0-15 practical salinity units (psu; 1 psu approximate to 1%omicron); reduced hatching occurred at 20 psu and no hatching occurred at 25-35 psu. By contrast, eggs exposed after 5 d to a slow change of salinity to freshwater over 48 h also hatched well at 0-15 psu, but they hatched at higher salinities as well. Fungal infections of eggs were greatest at 0 and 5 psu. Larvae exposed to an instantaneous change of salinity (0-25 psu) had the best survival rates at salinities of 0 psu (83%) and 5 psu (87%), but lower survival was obtained at 10 psu (49%) and 15 psu (22%) after 144 It. At 20 and 25 psu, larval mortality was 90% and 100%, respectively, after 48 It. In contrast, larvae exposed to a slow change of salinity over 48 h showed a higher salinity tolerance (43% survival at 20 psu), although higher salinities killed the fish. Juveniles had a high tolerance (100% survival) to a slow salinity change over 48 h at 0-25 psu. After 90 d, survival was best at 5-20 psu, optimal growth occurring at 5, 10, and 15 psu. Mortality was 100% in fish reared in freshwater after 75 d of culture, possibly a result of the high stress at this salinity. The osmolarity of muscle tissue of juveniles was not significantly different (P > 0.05) between trials, indicating efficient internal ionic regulation at all salinities. The wide salinity tolerance of blacknose silverside is clearly beneficial for its management and culture.

Keywords
10; 20; CHIROSTOMA; CULTURE; eggs; fish; freshwater; Growth; INFECTION; INFECTIONS; LAKE; LARVAE; LARVAL; Management; Mexico; MORTALITIES; MORTALITY; MUSCLE; objective; Practice; PROPORTION; RATES; Regulation; Stress; Survival; TISSUE; Tolerance; TRIAL; TRIALS; UNITS

Journal
North American Journal of Aquaculture: Volume 70, Issue 1