Saxatilia, Varella & Kullander & Menezes & Oliveira & López-Fernández, 2023

Varella, Henrique R, Kullander, Sven O, Menezes, Naércio A, Oliveira, Claudio & López-Fernández, Hernán, 2023, Revision of the generic classification of pike cichlids using an integrative phylogenetic approach (Cichlidae: tribe Geophagini: subtribe Crenicichlina), Zoological Journal of the Linnean Society 198 (4), pp. 982-1034 : 1022

Node 140— Saxatilia , new genus u r n:l s i d: z o o b a n k. o r g: a c t: 5 9 D 8 1 4 5 8 - A A 5 6 -

426D-BC9E-73781A861282

Type species: Perca saxatilis Linnaeus, 1758

Saxatilia is recovered as monophyletic with high support in the ML and BI trees (BS100%, PP 100%), and moderate to low support in the parsimony analysis based on EW/DiscreteMatrixTE (ABS 3/ RBS 43%; Table 6). This genus comprises 23 valid species and corresponds almost entirely to the C. saxatilis group, considered monophyletic in all previous studies since Ploeg (1991; see Fig. 3). Thirty-one unambiguous molecular transformations and 11 morphological synapomorphies (eight of them unambiguous) are optimized for the group ( Table 16).

Diagnosis: Species of Saxatilia can be diagnosed from all other pike cichlids by the presence of humeral blotch, which is evident from juvenile stages. Most species of Lugubria also have a dark blotch posterior to the pectoral fin that resembles a humeral blotch but appears only later in ontogeny. Species of Saxatilia are additionally distinguished from all pike cichlids by the combination of 31–71 scales in the E1 series, suborbital marking present, serrated preopercle, slender lachrymal, and sexual dimorphism in which males usually have light, small botches scattered on flanks and females show a round belly with a broad reddish or purplish pigmentation.

Saxatilia also differs from Hemeraia by having most scales on the flank ctenoid (combination of patterns 1 or 2 on the dorsal area and pattern B2 on the ventral area; see characters 25–26 and Supporting Information, Appendix S2, Fig. S2) vs. cycloid (combination of patterns 3 and B3; see characters 25–26 and Supporting Information, Appendix S2, Fig. S2). From Lugubria , Saxatilia differs by the number of vertebrae (31–36 vs. 38–42 in Lugubria ), from Wallaciia by the absence (vs. presence) of serrations on the posterior margin of supracleithrum, and from Teleocichla by all post-lachrymal infraorbitals autogenous (vs. infraorbitals 4 and 5 co-ossified), pelvic fin short and rounded with second ray longest (vs. pointed with third ray longest almost reaching genital papilla), and by the absence of osteological modifications related to rheophyly. Saxatilia is distinguished from the subgenus Crenicichla by the presence (vs. absence) of a dark blotch on the caudal fin and by cycloid (vs. ctenoid) scales on cheek and chest. From all species of the subgenus Batrachops of Crenicichla , except C. (B.) jegui , Saxatilia differs by the absence of a reticulate colour pattern on the flank (vs. having a reticulate pattern formed by the pigmentation on the base of each scale); and from the subgenus Lacustria of Crenicichla by a suborbital marking uniformly pigmented instead of formed by dark punctulations more or less scattered on the suborbital region.

Distribution: Saxatilia is the most widespread genus of pike cichlids, occurring in all major rivers of South America, including the Río Orinoco basin, the Amazon basin, all major drainages of the La Plata basin, the coastal drainages of Trinidad and Tobago, the Guianas, and Atlantic coastal drainages from north-eastern Brazil to the Lagoa dos Patos and Lagoa Mirim systems in southern Brazil and Uruguay. Recent collections from areas influenced by hydroelectric dams in coastal drainages in south-eastern Brazil (e.g. Río Paraíba do Sul) have shown the presence of Saxatilia (preliminarily identified as S. britskii ), but it is unclear if these records represent native distribution or recent human introductions.