Mango tilapia

Mango tilapia
Conservation status
Not evaluated (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Perciformes
Family:	Cichlidae
Genus:	Sarotherodon
Species:	S. galilaeus
Binomial name
Sarotherodon galilaeus (Linnaeus, 1758)
Subspecies
Sarotherodon galilaeus borkuanus (Pellegrin, 1919) Sarotherodon galilaeus boulengeri (Pellegrin, 1903) Sarotherodon galilaeus galilaeus (Linnaeus, 1758) Sarotherodon galilaeus multifasciatus (Günther, 1903) Sarotherodon galilaeus sanagaensis (Thys van den Audenaerde, 1966)
Synonyms
Sparus galilaeus Linnaeus, 1758 Chromis galilaeus (Linnaeus, 1758) Sarotherodon galilaeum (Linnaeus, 1758) Tilapia galilaea (Linnaeus, 1758) Tilapia galilaea galilaea (Linnaeus, 1758) Tilapia pleuromelas A. H. A. Duméril, 1861 Chromis pleuromelas (A. H. A. Duméril, 1861) Tilapia galilaea pleuromelas A. H. A. Duméril, 1861 Tilapia lateralis A. H. A. Duméril, 1861 Chromis lateralis (A. H. A. Duméril, 1861) Tilapia macrocentra A. H. A. Duméril, 1861 Chromis tiberiadis Lortet, 1883 Chromis microstomus Lortet, 1883 Tilapia microstoma (Lortet, 1883) Chromis multifasciatus Günther, 1903 Sarotherodon multifasciatus (Günther, 1903) Tilapia galilaea multifasciata (Günther, 1903) Tilapia multifasciatus (Günther, 1903) Tilapia boulengeri Pellegrin, 1903 Tilapia galilaea boulengeri Pellegrin, 1903 Tilapia borkuana Pellegrin, 1919 Tilapia galilaea borkuana Pellegrin, 1919 Tilapia sanagaensis Thys van den Audenaerde, 1966 Sarotherodon sanagaensis (Thys van den Audenaerde, 1966)

The mango tilapia (Sarotherodon galilaeus) is a species of fish from the cichlid family. Other common names include Galilaea tilapia, Galilee St. Peter’s fish, and St. Peter's fish.^[1] The nominate subspecies is a relatively large cichlid at up to 41 centimetres (16 in) in length and about 1.6 kilograms (3.5 lb) in weight,^[2] but its remaining subspecies are not known to surpass 13–16 centimetres (5.1–6.3 in) in length.^[3][4][5][6]

The widespread nominate subspecies is found in lakes, rivers and other fresh or brackish habitats in northern and central Africa, ranging as far south as the Guinea region, the Congo River Basin and Ethiopia. Outside Africa it is found in Syria, Jordan and Israel.^[2] It is one of the very few cichlids that is found in Africa north of the Sahara and in Asia. The typical temperature range is 22–28 °C (72–82 °F), but it has been recorded from waters as cold as 9 °C (48 °F).^[2] The remaining subspecies have much smaller distributions: S. g. borkuanus is found in Saharan oases in northern Chad,^[3] S. g. boulengeri is found in the lower and middle Congo River,^[4] S. g. multifasciatus is found in rivers in Côte d'Ivoire and western Ghana,^[5] and S. g. sanagaensis is found in the Sanaga River in Cameroon.^[6]

It is a bi-parental mouthbrooder. The mating strategies can vary. Both uni-parent and bi-parent mouthbrooding is used, and monogamous or polygamous behaviour.^[7]

Behavior

Mating

Mating is usually monogamous for St. Peter's fish. The male and female will create a depression in the substrate, in which the female will lay her eggs. Afterwards, the male will glide over the depression and fertilize the eggs. Mouth brooding is a tactic which, either male or female or both male and female, protects and carries the eggs in their mouth for a time period of about two weeks. However, pair bonding ends after mouth brooding begins.^[8]

Male Mate Choice

An experiment studying mate choice in St. Peter's Fish shows results of a the correlation between operational sex ratio, characteristics of the body and pairing. In this study, the fish were exposed to different OSR’s (more males, more females, or an equal ratio). Pair bonding was formed quicker between larger fish, and there was a long delay in pairing for the most abundant sex in the OSR. In addition, this study showed that St. Peters fish that mate within a similar size group have greater reproductive success.^[9]

Male Mating Style Flexibility and Parental Care

There is flexibility for male St. Peter's fish in their mating styles. During spawning, males can adapt the mating style of territoriality or non territoriality. Also, males can adapt other mating styles, like brooding participating or non participating in egg brooding and pairing or not pair bonding with the selected female. In addition to the multiple mating styles, the males show that they are able to select alternate reproductive styles (ARS), which are combinations of the mating styles that are mentioned above. Territoriality males were the most dominant group (which deserted the female after mating), but male reproductive behavior changes between different reproductive cycles. These mating styles are also important factors in parental care. There are many levels of parental care in St. Peter’s fish: uniparental and biparental parental care (male, female or both parents can all exist in one population).^[10][11]

For St. Peter's fish, parental care is important for the survival of the offspring.  Parents who shared the job of incubation had double the reproductive success of other parents who did the job alone. Rather, for uniparental parental care, the parent’s reproductive success for each brood was 20% higher. In terms of the relationship between caring strategies and clutch size, either parent is equally capable of caring for its offspring (both capable of taking care of the same number of eggs and fry). Levels of parental care in St. Peter's fish depend on the costs and benefits of staying versus departing. Some costs of both males and females were the growth and prolonged time until the next time they reproduce. In addition, parental care decreased a female’s future ability to reproduce (fecundity). This is plausible since a body weight increase increases fecundity. Female St. Peter's fish have high parental care costs, which can be thought to be separated in two parts: egg production cost and parental care cost. In experiments studying parents deserting their children, deserting was more frequent in males and females when there were higher parental care costs and males deserting was more frequent when there was a reduced benefits from parental care.^[8][11][12]

References

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