Apistogramma agassizii
Two male variants
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cichliformes
Family: Cichlidae
Genus: Apistogramma
Species:
A. agassizii
Binomial name
Apistogramma agassizii
(Steindachner, 1875)
Synonyms[1]
  • Geophagus agassizii Steindachner, 1875
  • Apistogramma agassizi (Steindachner, 1875)
  • Apistogramma parva Ahl, 1931

Apistogramma agassizii, commonly known as Agassiz's dwarf cichlid, is a species of cichlid found in the Marañón and Ucayali River in Peru, some tributaries of the Amazon River, as well as downstream to the estuary in the Atlantic.[2] It is named after the Swiss-American zoologist and geologist Louis Agassiz (1807-1873).[3]

Description

Apistogramma agassiziii is a small, sexual dimorphic, and territorial fish. The males are larger, more colorful, and have more prolonged fins compared to females of the species.[4] Body color and fin length are important characteristics during courtship and mating in the breeding seasons where larger males are more likely to control better quality territory and have more access to food. The larger and more colorful males are preferred by buyers of ornamental fish.

Both males and females undergo four developmental phases of gonad maturation: immature, developing, spawning capable, and regressing. Mature females release a single batch of oocytes once in each breeding season. However spawning is partial - not all Apistogramma agassiziii spawn at the same time. This is possibly an evolutionary adaptation to extreme seasonal changes, i.e. changes in water level, that ensures the resilience of the species by continuously introducing new, young individuals into the population.[5]

The diet of Apistogramma agassiziii varies depending on habitat. In forest areas, the diet is mainly adult insects and insect fragments, whereas in a pasture environment, Apistogramma agassizii prefers the larvae of insects such as Diptera species.[6]

Distribution and habitat

Apistogramma agassizii lives in shallow waters, endemic to the Amazon basin. It prefers habitats with minimal current where plant debris, particularly dead leaves, accumulate as shelter from predators, both larger fishes and aerial predators.[7] Of the 94 species of Apistogramma considered valid, Apistogramma agassizii, along with Apistogramma cacatuoides and Apistogramma bitaeniata, is one of the very few with a large distribution range.

Taxonomy

Numerous researchers have suggested that the wide range suggests that Apistogramma agassizii is actually more than one distinct species.[8] A study by Estivals et al. (2020) in the Peruvian Amazon showed at least three separate genotypic clusters and estimated that the Apistogramma agassizii designation actually holds "tens of species".[2] Using molecular dating, they estimated that the three proposed species would have begun to diverge from the most recent common ancestor during the Plio-Pleistocene period, which greatly affected river dynamics and could have created geological restrictions between the different clusters, leading to species divergence. As a result, they propose that Apistogramma agassizii no longer be considered a single, widespread taxon, but rather a mosaic of species with distinct, but still unknown, geographical distribution.

Relationship to humans

In aquaria

Just like all dwarf cichlids, Apistogramma agassizii requires weekly partial water changes in order to keep the nitrate levels as low as possible. It prefers a hardness level of 50–100 mg/L and a pH of 6.0.

They should be housed in an aquarium of at least 10 gallons. In order to reduce problems arising from their territorial nature, it is important to break up lines of sight within the aquarium, something that can be achieved with bogwood, root ornaments and hardy plants. They should not be kept in the same aquarium as other dwarf cichlids. A better choice of tankmates would be a shoal of tetras or other small fish native to the Amazon River.[9]

Threats

Apistogramma agassizii is affected by increasing water temperatures due to climate change. These effects can be exacerbated by deforestation, which affects the ability of Apistogramma agassizii, other Apistogramma species, and other stream fishes to cope with changes in water temperature and quality. Additionally, fishermen along the Amazon have been known to use barbasco, a plant-derived, non-specific ichthyotoxin that kills almost all fish in the area when used.[2] Apistogramma agassizii is also highly sensitive to copper exposure, an increasing concern due to growing metal contamination in the Amazon.[10]

See also

Sources

References

  1. ↑ Froese, Rainer; Pauly, Daniel (eds.) (2018). "Apistogramma agassizii" in FishBase. June 2018 version.
  2. 1 2 3 Estivals, Guillain; Duponchelle, Fabrice; Römer, Uwe; García‐Dávila, Carmen; Airola, Etienne; Deléglise, Margot; Renno, Jean‐François (August 2020). "The Amazonian dwarf cichlid Apistogramma agassizii (Steindachner, 1875) is a geographic mosaic of potentially tens of species: Conservation implications". Aquatic Conservation: Marine and Freshwater Ecosystems. 30 (8): 1521–1539. doi:10.1002/aqc.3373. ISSN 1052-7613. S2CID 225350124.
  3. ↑ Christopher Scharpf & Kenneth J. Lazara (22 September 2018). "Order CICHLIFORMES: Family CICHLIDAE: Subfamily CICHLINAE (d-w)". The ETYFish Project Fish Name Etymology Database. Christopher Scharpf and Kenneth J. Lazara. Retrieved 17 November 2018.
  4. ↑ Oliveira, Jomara Cavalcante de; Amadio, Sidinéia Aparecida; Queiroz, Helder Lima de (2017). "Populacional structure of Apistogramma agassizii (Steindachner, 1875) (Perciformes: Cichlidae) in aquatic environments of the Amana Sustainable Development Reserve (Amazonas – Brazil)". Acta of Fisheries and Aquatic Resources. 5 (3): 61–67. doi:10.2312/Actafish.2017.5.3.6167 (inactive 1 August 2023). ISSN 2357-8068.{{cite journal}}: CS1 maint: DOI inactive as of August 2023 (link)
  5. ↑ de Oliveira, Jomara Cavalcante; de Queiroz, Helder Lima (2017-11-01). "Life history traits of two dwarf cichlids species in the white waters of the Amazonian floodplain". Environmental Biology of Fishes. 100 (11): 1497–1505. doi:10.1007/s10641-017-0660-8. ISSN 1573-5133. S2CID 38140981.
  6. ↑ Virgilio, Lucena Rocha; Brito, Cleyton Holanda de; Suçuarana, Monik da Silveira; Vieira, Lisandro Juno Soares (2020). "Forest fragmentation influences the diet of cichlids Apistogramma agassizii (Steindachner, 1875) and Aequidens tetramerus (Heckel, 1840) (Actinopterygii: Cichliformes) in streams of the Western Amazon". Acta Limnologica Brasiliensia. 32. doi:10.1590/s2179-975x2618. ISSN 2179-975X. S2CID 229663531.
  7. ↑ Kochhann, Daiani; Campos, Derek Felipe; Val, Adalberto Luis (2015-12-01). "Experimentally increased temperature and hypoxia affect stability of social hierarchy and metabolism of the Amazonian cichlid Apistogramma agassizii". Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology. 190: 54–60. doi:10.1016/j.cbpa.2015.09.006. ISSN 1095-6433. PMID 26387464.
  8. ↑ Britzke, Ricardo [UNESP (2015-02-26). "Relações filogenéticas do gênero Apistogramma (Teleostei, Cichlidae) e filogeografia da espécie Apistogramma agassizi". Aleph: 187 f.
  9. ↑ Apistogramma Agassizii http://aquaristmagazine.com/Apistogramma%20Agassizii.html Archived 2012-09-01 at the Wayback Machine
  10. ↑ Braz-Mota, Susana; Campos, Derek F.; MacCormack, Tyson J.; Duarte, Rafael M.; Val, Adalberto L.; Almeida-Val, Vera M. F. (2018-07-15). "Mechanisms of toxic action of copper and copper nanoparticles in two Amazon fish species: Dwarf cichlid (Apistogramma agassizii) and cardinal tetra (Paracheirodon axelrodi)". Science of the Total Environment. 630: 1168–1180. Bibcode:2018ScTEn.630.1168B. doi:10.1016/j.scitotenv.2018.02.216. hdl:11449/170734. ISSN 0048-9697. PMID 29554738. S2CID 3984098.

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