European jackal
The European jackal is the largest of the golden jackals, with animals of both sexes measuring 120–125 cm (47–49 in) in total length and 10–13 kg (20–29 lb) in body weight. One adult male in North-Eastern Italy is recorded to have reached 14.9 kg (33 lb). The fur is coarse, and is generally brightly coloured with blackish tones on the back. The thighs, upper legs, ears and forehead are bright reddish chestnut. Jackals in Northern Dalmatia have broader than average skulls, which is thought to result from human induced isolation from other populations, thus resulting in a new morphotype.
Crevalle jack
The crevalle jack reaches sexual maturity at different lengths in males and females, with estimates suggesting males reach maturity at 55 cm and four to five years of age, and females at 66 cm and five to six years of age. Reproduction is thought to occur year-round in most areas, although there are peaks in activity. South of Florida, this period is between March and September, in Cuba it is April and May, while in Jamaica no definitive peak has yet been identified. The species also has a protracted spawning in Ghana, although a peak in activity occurs between October and January. Juveniles are also present in lagoons year round in this location, indicating year round spawning and recruitment. The place of spawning also appears to be variable, with the act occurring offshore south of Florida, while in Colombia and Belize, they have been observed spawning over inshore reefs and bays. Large aggregations of crevalle jack form prior to spawning, with these schools containing upward of 1000 individuals. Pairs break off from the school to spawn, with one individual turning a much darker color during this exchange. Once spawning has occurred, the pair rejoins the main school. Fecundity in the species has been estimated as up to one million eggs, with these being pelagic, and spherical in shape. They have a diameter of 0.7 to 0.9 mm, and contain a pigmented yolk and one yellow oil globule with dark pigments. The larvae have been extensively described in the scientific literature, although the sequence of fin formation is still not well known. Defining features of the larval crevalle jack include a relatively deep body, heavily pigmented head and body, and more detailed meristic characteristics, with flexion occurring at 4 to 5 mm in length.