Crenicichla is a genus of the subfamily Cichlinae, tribe Crenicichlini. It is most closely related to Teleocichla.
Crenicichla includes more than 80 species, many of them presently undescribed. Morphological variation, especially in snout and jaw shape is considerable, although still not extensively documented.
The following derived characters may justify recognition of Crenicichla until a thorough cladistic analysis has been performed. As in Teleocichla the supraoccipital crest is absent, but in contrast to Teleocichla there is a spinous caudal projection in Crenicichla which may be an autapomorphy of that genus. In Teleocichla there is only a slight strengthening or short bilateral processes to serve as attachment for the supracarinalis tendon. Crenicichla species usually have five separate infraorbitals, each separately innervated; in other cichlids, including Teleocichla the second and third infraobital bones are usually co-ossified terminally, retaining the opposed terminal foramina of the separate bones as a mesial foramen. Crenicichla hemera, however, has co-ossified second and third infraorbitals. The vertebral column in Crenicichla has more abdominal than caudal vertebrae, unlike most cichlids which have equal numbers or more caudal than abdominal vertebrae. Stiassny (1982) hypothesized that a higher ratio of abdominal to caudal vertebrae would be a synapomorphy of Cichla and Crenicichla.
Using scale counts, Kullander (1991) distinguished two major groups among Crenicichla species; the large-scaled species with E1 scale counts 70 or less, and the small-scaled with E1 scale counts 80 or more. Crenicichla jegui (E1 scales 76-82) apparently extends the range for small-scaled species, but still there is no overlap bridging the 70-80 gap.
The Crenicichla lugubris species group, recognized for the small-scaled Crenicichla species can be separated into two groups.
The first is characterized by a blunt snout and generally more than 110 scales in the E1 row: C. lugubris, C. adspersa, C. lenticulata, C. strigata, C. cincta, C. johanna (with 90-110 E1 scales), C. rosemariae and C. marmorata. It corresponds to species 16-22 in Regan's (1913) key. As far as is known, these species undergo a more or less drastic ontogenetic change in colour pattern (Kullander, 1986; Stawikowski & Werner, 1989, p. 262ff.) and most species have a spotted head when young (C. adspersa, C. lenticulata, C. marmorata, C. strigata, C. johanna).
The species with pointed snout and 80-110 scales were contained by Ploeg (1991) in the lugubris group but they may be distinguished by a dorsoventrally compressed, pointed snout and mostly fewer than 110 E1 scales (Kullander, 1991): C. acutirostris (E1 scales 103-111), C. jegui (E1 scales 76-82), C. multispinosa (E1 scales 89-97), C. percna (E1 scales 95-104), C. phaiospilus (E1 scales 94-110), C. ternetzi (E1 scales 80-91), and C. vittata (E1 scales 80-90). These do not undergo drastic ontogenetic change of colour pattern and young apparently do not have a dark spotted head.
The Crenicichla saxatilis group includes species with fairly large scales, less than 70, and of fairly small size, less than 30 cm, and usually only 15-20 cm SL. Practically all species have a distinct humeral blotch, usually with a light rim around it, situated across or below upper lateral line scales. A homologous marking is always present, but in some species may be little differentiated from the anterior portion of the lateral band. There is usually a narrow black stripe below they eye. Females have ocellated spots in the dorsal fin, or a contrasting black marginal and white submarginal band. These species are found all over the range of the genus except along the south Brazilian coast between the Rio Jacui and the Rio São Francisco, both in lowlands and at a few hundred meters elevation: Crenicichla albopunctata, C. alta, C. anthurus, C. brasiliensis, C. britskii, C. coppenamensis, C. frenata, C. hummelincki, C. inpa, C. labrina, C. lepidota, C. lucius, C. menezesi, C. nickeriensis, C. proteus, C. pydanielae, C. santosi, C. saxatilis, C. semicincta, C. sipaliwini, C. sveni, C. vaillanti.
The Crenicichla reticulata group is often separated as a distinct genus, Batrachops. It includes a range of species, often with fewer, more firmly implanted teeth than other Crenicichla, and always with a colour pattern consisting of vertical bars from juvenile to adult. Scale counts range generally between 50 and 70. There is a dark spot at the margin of each scale. The caudal ocellus as a rule is well developed. Sizes vary from 10 to 30 cm. Some of these species, viz. C. cametana, C. cyclostoma, C: geayi, C. sedentaria, occur in fast running water, but C. reticulata, C. cyanonotus, C. stocki and C. semifasciata are lowland quiet water fishes.
The Crenicichla wallacii group includes small species, less than 80 mm SL, with fairly large eyes and plain sides, the caudal spot either small and ocellated or appearing as a large midbasal blotch. Sex dimorphism is marked in some, with females having large ocellated spots in the dorsal fin, but sexes may also be isochromatic, at least in preservative. In distinction to other Crenicichla the supracleithrum is serrated in most species. All species are found in Amazonian, Guianan and Orinocoan lowlands, and in the Tocantins, predominantly in black or clear waters. The group was reviewed independently by Ploeg (1991) and Kullander (1990a), from slightly different angles. Crenicichla notophthalmus, C. regani, C. urosema, C. wallacii, probably also C. heckelii, C. compressiceps and C. virgatula.
The Crenicichla scottii group consists of three species, viz. C. scottii, C. gaucho and C. prenda, restricted to the Uruguay and nearby Argentina. Sizes range between 85 and ca 300 mm SL. Lucena & Kullander (1992) characterised this group by wide interorbital space, maxilla extending well beyond a vertical from the anterior margin of the orbit, lachrymal bone wider than deep (as in saxatilis group species), and a wide lateral band, continuous from head to caudal fin.
The Crenicichla missioneira group consists of the Uruguaian endemic species C. missioneira, C. minuano, C. tendybaguassu, C. igara and C. jurubi. They grow to about 20 cm SL. Scale counts range between 52 and 68. Lucena & Kullander (1992) characterised the group by smooth preopercular margin, suborbital stripe reduced to one or a few spots just below eye, caudal spot situated immediately at base of caudal fin instead of slightly removed from it, and posttemporal blotch well developed and frequently ocellated.
The Crenicichla lacustris group is currently under work by Kullander & Lucena. Those species, including C. lacustris, C. dorsocellata and C. punctata may be recognized by extensively spotted sides and fins. They reach about 30 cm SL and have about 60-70 scales in a lateral row.
The type species, C. macrophthalma, cannot be assigned to any particular group. It with extremely large eyes and the only species with ctenoid predorsal scales. Lateral scales number about 60-70. It reaches about 20 cm SL and is restricted to the central Amazon basin.
CASCIOTTA, J.R. 1987. Crenicichla
celidochilus n.sp. from Uruguay and a multivariate analysis
of the lacustris group. Copeia 1987: 883-891.
EIGENMANN, C.H. & W.L. BRAY. 1894. A revision of the American Cichlidae. Ann. N.Y. Acad. Sci. 7: 607-624.
HECKEL, J. 1840. Johann Natterer's neue Flussfische Brasilien's nach den Beobachtungen und Mittheilungen des Entdeckers beschrieben. (Erste Abtheilung, die Labroiden.) Annln wien. Mus. Natges. 2: 327-470.
KULLANDER, S.O. 1981a. A cichlid from Patagonia. Buntbarsche Bulletin, American Cichlid Association (85): 13-23.
KULLANDER, S.O. 1981b. Cichlid fishes from the La Plata basin. Part I. Collections from Paraguay in the Muséum d'Histoire naturelle de Genève. Revue Suisse de Zoologie 88: 675-692.
KULLANDER, S.O. 1982. Cichlid fishes from the La Plata basin. Part III. The Crenicichla lepidota species group. Revue Suisse de Zoologie 89: 627-661.
KULLANDER, S.O. 1986. Cichlid fishes of the Amazon River drainage of Peru. Swedish Museum of Natural History, Stockholm.
KULLANDER, S.O. 1988. Teleocichla, a new genus of South American rheophilic cichlid fishes with six new species. Copeia 1988: 196-230.
KULLANDER, S.O. 1990a. A new species of Crenicichla from the Rio Tapajós, Brazil, with comments on interrelationships of small crenicichline cichlids. Ichthyol. Explor. Freshwaters 1: 85-94.
KULLANDER, S.O. 1990b. Crenicichla hemera, a new cichlid species from the Rio Aripuanã drainage, Mato Grosso, Brazil. Ichthyological Exploration of Freshwaters 1:213-218.
KULLANDER, S.O. 1991. Crenicichla phaiospilus and C. percna, two new species of pike cichlids from the Rio Xingu, Brazil. Ichthyological Exploration of Freshwaterss 1:351-360.
KULLANDER, S.O. & H. NIJSSEN. 1989. The cichlids of Surinam. E.J. Brill, Leiden and other cities.
LUCENA, C.A.S. de & P.V. de AZEVEDO. 1989. Crenicichla punctata Hensel, 1870 uma espécia [sic] válida de ciclídeo para o sul do Brasil. Comun. Mus. Ciênc. PUCRS (Zool.) 2: 87-105.
LUCENA, C.A.S. de & S.O. KULLANDER . 1992. The Crenicichla species of the Uruguai River drainage in Brazil. Ichthyological Exploration of Freshwaters 3: 97-160.
MAC DONAGH, E.J.1937. Estudios zoologicos en el Rio Negro inferior. Revta Mus. La Plata (N.S.) 1936: 166-173
PELLEGRIN, J. 1904. Contribution à l'étude anatomique, biologique et taxinomique des poissons de la famille des cichlidés. Mémoires de la Société zoologique de France 16: 41-399.
PERUGIA, A. 1897. Di alcuni pesci raccolti nell'alto Paraguay dal Cav. Guido Boggiani. Ann. Mus. civ. Stor. nat. Genova (2) 18: 147-150.
PLOEG, A. 1986. The cichlid genus Crenicichla from the Tocantins River, State of Pará, Brazil, with descriptions of four new species. Beaufortia 36: 57-80
PLOEG, A. 1986. Occurrence and variability of Crenicichla saxatilis (Linnaeus, 1758) in Surinam, and restriction of its type-locality. Bijdragen tot de Dierkunde 56: 47-59.
PLOEG, A. 1986. The fishes of the cichlid genus Crenicichla in French Guiana. Bijdragen to de Dierkunde 56: 221-231.
PLOEG, A. 1987. Crenicichla marmorata Pellegrin, 1904 du bassin du Rio Trombetas, Brésil, nouvelle description illustrée. Revue fr. Aquariol. 14: 85-88.
PLOEG, A. 1987. Review of the cichlid genus Crenicichla Heckel, 1840 from Surinam, with descriptions of three new species. Beaufortia 37: 73-98.
PLOEG, A. 1991. Revision of the South American cichlid genus Crenicichla Heckel, 1840, with descriptions of fifteen new species and considerations on species groups, phylogeny and biogeography. Academisch Proefschrift, Universiteit van Amsterdam.
PLOEG, A., M. JÉGU & E. FERREIRA. 1991. Crenicichla tigrina, une nouvelle espèce de Cichlidae du Rio Trombetas, Pará, Brésil. Bull. zoöl. Mus. Univ. Amsterd. 13: 1-11.
REGAN, C.T. 1905. A revision of the fishes of the South-American cichlid genera Crenacara, Batrachops, and Crenicichla. Proceedings of the Zoological Society, London 1905: 152-168.
REGAN, C.T. 1913. A synopsis of the cichlid fishes of the genus Crenicichla. Annals and Magazine of Natural Hististory (8) 11: 498-540.