Reproductive biology of the dolphin fish Corphaena hippurus on the east coast of Taiwan

Abstract

The dolphin fish, Corphaena hippurus Linnaeus, is one of the most important migratory fishes on the east coast of Taiwan. Present results are based on an investigation of 1439 specimens caught using long‐line and driftnet, and set net collected monthly between September 1996 and September 1997. The sex ratio of female to male and female combined was 65%, demonstrating a female predominance. Oocytes became mature and transparent when they attained 1.0 mm in diameter. The total number of oocytes per ovary was estimated to range from 2.78 × 105 to 23.48 × 10>5, but batch fecundity was noticeably lower than the total number of ovarian eggs, ranging 5.3–32.7% (average 30.1%), and the relative fecundity ranging 10–344/g bodyweight (mean 111/g bodyweight). Minimum body size at sexual maturity was estimated to be 51 cm for both sexes. Dolphin fish spawned throughout the year with reproductive activity peaking in February to March. It is suggested that the dolphin fish has an extended spawning season, during which it lays eggs almost continuously.

Reproductive biology of the squirrelfish, <i>Holocentrus adscensionis</i> (Osbeck, 1765), caught off the coast of Pernambuco, Brazil

“…Nevertheless, according to Vazzoler (1996) and Wu et al (2001), this ratio might differ from 1:1 due to different growth rates, mortality rates and longevity for each sex, sexual inversion and migration to spawning grounds.…”

Tácticas reproductivas para optimizan la supervivencia de la descendencia de Cichlasoma orientale (Perciformes: Cichlidae)

“…orientale differs from the majority of teleosts by the larger size of the male. These differences in sexual ratio have been explained by different hypothesis, such as physiological differences between sexes, mechanisms that makes males more inclined to be captured or less inclined to natural mortality (Boussou et al, 2010), growth rates (Kume & Joseph, 1966) and longevity (Wu, Su, & Kawasaki, 2001). Usually, a larger body volume would allow the female to allocate more eggs and therefore might be considered an evolutionary advantage (Moraes et al, 2013).…”

Reproductive biology of dolphinfish, <em>Coryphaena hippurus</em> (Actinopterygii: Coryphaenidae), in Saint Peter and Saint Paul Archipelago, Brazil

“…Potoschi et al (1999), working with individuals from the Mediterranean Sea, found the highest values of GSI between June and September, when all the individuals sampled were mature, with a peak in July. Wu et al (2001) found peaks of GSI for males and females in February and March in Taiwan, but suggested that the dolphinfish has a long breeding season, during which it spawns almost continuously. Similarly, Alejo-Plata et al (2011) observed a long spawning season for the dolphinfish off Mexico, with several peaks of GSI and the top two happening in September-November and between February and April.…”