Lates
Lates is a genus of perch-like predatory fishes in the family Latidae, consisting of approximately 13 species distributed across tropical Africa, the Indian Ocean, and the Indo-Pacific region, primarily inhabiting freshwater and brackish environments though some exhibit euryhaline tolerances.[1][2] These medium- to large-sized species, often reaching lengths exceeding 1 meter and weights up to 200 kg in the case of L. niloticus, feature fusiform bodies adapted for active predation on smaller fish and invertebrates.[3][4] Prominent among the genus is Lates niloticus, the Nile perch, native to African river systems including the Nile, Chad, and Niger basins, where it occupies deep waters as an adult apex predator while juveniles favor shallower habitats.[3] Its introduction to Lake Victoria in the mid-20th century precipitated a dramatic shift in the lake's ecosystem, driving the decline or local extinction of hundreds of endemic cichlid species through predation and competition, though it simultaneously established a valuable commercial fishery yielding substantial economic returns.[5][6] Another key species, Lates calcarifer (barramundi or Asian sea bass), exemplifies catadromous migration patterns, breeding in coastal marine waters before juveniles ascend rivers, and serves as a cornerstone of aquaculture due to its rapid growth, protandrous hermaphroditism, and adaptability to varied salinities.[7][8] The genus's ecological and economic significance is underscored by its role in both wild fisheries and intensive farming, yet introductions beyond native ranges have highlighted risks of biodiversity disruption, as evidenced by the Nile perch's impacts, prompting assessments classifying it as a high-risk invasive in non-native contexts.[9][10] Taxonomically, Lates falls within the order Carangaria, reflecting molecular phylogenetic alignments that distinguish Latidae from related perch families.[1]Taxonomy and Classification
Etymology
The genus name Lates originates from the New Latin form of the Ancient Greek word λάτος (látos), denoting the Nile perch, which serves as the type species L. niloticus.[11] This classical term was adopted by Georges Cuvier when he established the genus in 1828 within the Histoire naturelle des poissons, reflecting the longstanding recognition of the flagship species in Mediterranean and African ichthyological literature.[12] Some interpretations link the name to the Latin verb latere (to lurk or be hidden), alluding to the ambush predatory habits of species in the genus, though the primary linguistic root traces to the Greek descriptor for the fish itself.[13]Phylogenetic Relationships
The genus Lates belongs to the family Latidae, which is monophyletic and comprises three extant genera: Lates, Psammoperca, and Hypopterus.[14] Phylogenetic analyses based on whole mitochondrial genomes confirm the monophyly of Lates within Latidae, with strong support from concatenated gene sequences.[15] The family Latidae originated in the marine waters of the Tethys Sea during the Paleocene, with fossil evidence indicating widespread distribution across Africa, Europe, and Asia by the Oligocene.[16] [17] Latidae forms a sister group to Centropomidae (snooks) within the broader Percomorpha clade, as resolved by multi-gene molecular phylogenies incorporating mitochondrial and nuclear markers.[18] [19] Within Lates, Indo-Pacific and African lineages diverge early, with African species forming a monophylum that includes Nile perch (L. niloticus and congeners) and the four endemic species of Lake Tanganyika (L. stappersii, L. microlepis, L. mariae, L. angustifrons).[20] However, Nile perch exhibits paraphyly relative to the Tanganyika radiation, which colonized the lake relatively recently (estimated <1-2 million years ago) rather than representing an ancient divergence.[20] [21] Interspecific relationships among African Lates are supported by analyses of mitochondrial DNA (e.g., cytochrome b, control region) and nuclear loci, revealing low genetic divergence among Tanganyika endemics consistent with recent adaptive radiation in freshwater habitats.[22] [23] Fossil records, including Eocene and Oligocene taxa like †Eolates, reinforce Latidae's marine ancestry and subsequent invasions of freshwater systems, with Lates proper emerging by the late Oligocene in both African freshwater and Indo-Pacific marine deposits.[24] [25]Extant Species
The genus Lates includes 11 recognized extant species, all belonging to the family Latidae, with a distribution centered in freshwater and brackish environments of Africa and the Indo-Pacific.[26] These species are typically large predatory perches, varying in maximum size from about 50 cm to over 200 cm total length. The following table lists the extant species, including scientific nomenclature and primary distributions:| Scientific Name | Authority | Common Name | Primary Distribution |
|---|---|---|---|
| Lates angustifrons | Boulenger, 1906 | Tanganyika lates | Africa (Lake Tanganyika) |
| Lates calcarifer | Bloch, 1790 | Barramundi | Indo-West Pacific |
| Lates japonicus | Katayama, 1984 | Japanese lates | Northwest Pacific |
| Lates lakdiva | Pethiyagoda, 2012 | - | Asia |
| Lates longispinis | Worthington, 1932 | Rudolf lates | Africa (Lake Turkana) |
| Lates macrophthalmus | Worthington, 1929 | Albert lates | Africa (Lake Albert) |
| Lates mariae | Steindachner, 1909 | Bigeye lates | Africa |
| Lates microlepis | Boulenger, 1898 | Forktail lates | Africa |
| Lates niloticus | Linnaeus, 1758 | Nile perch | Africa (Nile River basin) |
| Lates stappersii | Boulenger, 1914 | Sleek lates | Africa (Lake Tanganyika) |
| Lates uwisara | Pethiyagoda, 2012 | - | Asia |