| intra- and interspecific mitochondrial dna sequence variation within two species of rock-dwelling cichlids (teleostei: cichlidae) from lake malawi, africa. | difficulties in interpreting the evolutionary significance of lake malawi cichlid morphologies led us to examine molecular techniques for resolving relationships among closely related species. mitochondrial dna (mtdna) sequence variation in the first half of the control region (445 bp) was examined within and between two species of melanochromis, a genus of rock-dwelling cichlids from lake malawi, africa. the mean number of pairwise differences observed within melanochromis auratus (boulenger) a ... | 1994 | 8025732 |
| major-histocompatibility-complex variation in two species of cichlid fishes from lake malawi. | lake malawi in eastern africa harbors > 500 endemic species of cichlid fishes, all of which are believed to have emerged from a single founding population in the past 2 myr. molecular characterization of differences among the species could provide important information about the nature of speciation in the period of adaptive radiation. because of the close relationship, however, molecular variation among the species has been difficult to ascertain. in this communication, we provide evidence for ... | 1993 | 8412649 |
| isolation and characterization of microsatellite loci in the cichlid fish pseudotropheus zebra. | | 1997 | 9131814 |
| a line2 repetitive dna sequence from the cichlid fish, oreochromis niloticus: sequence analysis and chromosomal distribution. | we report the cloning and characterization of a long interspersed nucleotide element (line) from a cichlid fish, oreochromis niloticus, and show the distribution of this element, called ciline2 for cichlid line2, in the chromosomes of this species. the identification of an open reading frame in ciline2 with amino acid sequence similarity to reverse transcriptases encoded by line-like elements in caenorhabditis elegans, platemys spixii, schistosoma mansoni, gallus gallus (cri), drosophila melanog ... | 1999 | 10654084 |
| visual pigments of african cichlid fishes: evidence for ultraviolet vision from microspectrophotometry and dna sequences. | we have found evidence for ultraviolet visual capabilities in a lake malawi cichlid fish, metriaclima zebra. microspectrophotometry of single cones revealed a visual pigment with peak sensitivity at 368+/-4 nm. m. zebra also expresses a putative ultraviolet opsin gene whose sequence is closely related to the sws-1 opsin for other fishes. several other african cichlids have a functional copy of this uv gene in their genomic dna, but do not appear to express this gene as adults. these results sugg ... | 2000 | 10720660 |
| extensive homoplasy, nonstepwise mutations, and shared ancestral polymorphism at a complex microsatellite locus in lake malawi cichlids. | recent studies have suggested that size homoplasy is a prevalent feature of microsatellites and is expected to increase with time of divergence among populations and taxa. in this study, we performed sequence analysis of alleles from a complex microsatellite locus (pzeb4, initially isolated from pseudotropheus (maylandia) zebra) from 1 midwater-feeding and 10 rock-dwelling cichlid fish species from lake malawi, east africa, to investigate how widespread size homoplasy is among closely related ta ... | 2000 | 10742041 |
| assessing morphological differences in an adaptive trait: a landmark-based morphometric approach. | east african cichlid fishes have evolved a stunning array of oral jaw morphologies. to better understand the adaptive evolution of this trait, we performed a morphological analysis of the jaws of two closely related species from lake malawi that have very different modes of feeding. labeotropheus fuelleborni forages along the substrate with a "biting" mode of feeding, while metriaclima zebra feeds in the water column with a "sucking" mode. we analyzed each of the four skeletal elements that make ... | 2001 | 11351326 |
| cone opsin genes of african cichlid fishes: tuning spectral sensitivity by differential gene expression. | spectral tuning of visual pigments is typically accomplished through changes in opsin amino acid sequence. within a given opsin class, changes at a few key sites control wavelength specificity. to investigate known differences in the visual pigment spectral sensitivity of the lake malawi cichlids, metriaclima zebra (368, 488, and 533 nm) and dimidiochromis compressiceps (447, 536, and 569 nm), we sequenced cone opsin genes from these species as well as labeotropheus fuelleborni and oreochromis n ... | 2001 | 11470845 |
| algal dermatitis in cichlids. | three varieties of a popular african cichlid aquarium species, pseudotropheus zebra, from 2 tropical fish farms in east central florida were submitted for diagnostic evaluation because of the development of multifocal green lesions. the percentage of infected fish in these populations varied from 5 to 60%. fish were otherwise clinically normal. microscopic examination of fresh and fixed lesions confirmed algal dermatitis, with light invasion of several internal organs in each group. a different ... | 2002 | 11991415 |
| phylogeography of lake malawi cichlids of the genus pseudotropheus: significance of allopatric colour variation. | one of the most compelling features of the cichlid fishes of the african great lakes is the seemingly endless diversity of male coloration. colour diversification has been implicated as an important factor driving cichlid speciation. colour has also been central to cichlid taxonomy and, thus, to our concept of species diversity. we undertook a phylogeographical examination of several allopatric populations of the lake malawi cichlid pseudotropheus zebra in order to reconstruct the evolutionary h ... | 2002 | 12573062 |
| laboratory mating trials indicate incipient speciation by sexual selection among populations of the cichlid fish pseudotropheus zebra from lake malawi. | it has been suggested that sexual selection may have played a major role in the rapid evolution of hundreds of species of cichlid fishes in lake malawi. we report the results of a laboratory test of assortative mating among lake malawi cichlid fishes from five closely related geographical populations differing in male courtship colour. paternity of clutches was tested using microsatellite dna typing of offspring. out of 1955 offspring typed, 1296 (66.3%) were sired by the male from the same popu ... | 2004 | 15209099 |
| hybridization and contemporary evolution in an introduced cichlid fish from lake malawi national park. | rapidly evolving systems offer the chance to observe genetic and phenotypic change in real time. we exploit a well-characterized introduction of cichlid fish into lake malawi national park to document a short history of habitat colonization and the evolution of genes and colour pattern. in the early 1960s, a fish exporter introduced individuals of cynotilapia afra to a single site (mitande point) of thumbi west island and, as late as 1983, the species was confined to this location. in 2001, c. a ... | 2004 | 15245419 |
| a new genus and species of macroderoididae, and other digeneans from fishes of lake malawi, africa. | malawitrema staufferi n. gen., n. sp., an unusual digenean, is described from clarias mossambicus (type host) and bagrus meridionalis from lake malawi. it has a small, pyriform body, with a spinous tegument. the ceca are relative short, not reaching to the testes. the 2 testes are symmetrical in the middle hind body. the cirrus sac is long and narrow, reaching into hind body. the genital pore is median, immediately anterior to the ventral sucker. the ovary is pretesticular, and a canalicular sem ... | 2007 | 17918366 |
| construction of bacterial artificial chromosome libraries for the lake malawi cichlid (metriaclima zebra), and the blind cavefish (astyanax mexicanus). | teleost fishes have become important models for studying the evolution of the genetic mechanisms of development. a key resource for comparative genomics and positional cloning are large-insert libraries constructed in bacterial artificial chromosomes. we have constructed bacterial artificial chromosome libraries for two species of teleost fish that are important models for the study of developmental evolution. metriaclima zebra is one of several hundred closely related, morphologically diverse, ... | 2007 | 18041941 |
| annotation of expressed sequence tags for the east african cichlid fish astatotilapia burtoni and evolutionary analyses of cichlid orfs. | the cichlid fishes in general, and the exceptionally diverse east african haplochromine cichlids in particular, are famous examples of adaptive radiation and explosive speciation. here we report the collection and annotation of more than 12,000 expressed sequence tags (ests) generated from three different cdna libraries obtained from the east african haplochromine cichlid species astatotilapia burtoni and metriaclima zebra. | 2008 | 18298844 |
| courtship and agonistic sounds by the cichlid fish pseudotropheus zebra. | courtship and agonistic interactions in an african cichlid species present a richer diversity of acoustic stimuli than previously reported. male cichlids, including those from the genus pseudotropheus (p.), produce low frequency short pulsed sounds during courtship. sounds emitted by p. zebra males in the early stages of courtship (during quiver) were found to be significantly longer and with a higher number of pulses than sounds produced in later stages. during agonistic intrasexual quiver disp ... | 2008 | 18681618 |
| assortative mating among lake malawi cichlid fish populations is not simply predictable from male nuptial colour. | research on the evolution of reproductive isolation in african cichlid fishes has largely focussed on the role of male colours and female mate choice. here, we tested predictions from the hypothesis that allopatric divergence in male colour is associated with corresponding divergence in preference. | 2009 | 19265521 |
| elevated mtdna diversity in introduced populations of cynotilapia afra (günther 1894) in lake malawi national park is evidence for multiple source populations and hybridization. | genetic variation in many invasive species shows little or no signs of a founder event, suggesting that high genetic diversity may facilitate establishment success. the rocky-shore, plankton-feeding cichlid fish cynotilapia afra is endemic to lake malawi, but naturally absent from many suitable sites. in the 1960s, this species was introduced to the southern areas of the lake, presumably as a result of the aquarium fish trade. it has now become established on a number of rocky areas within the l ... | 2009 | 19793202 |
| histochemical study on the intestine goblet cells in cichlid and poecilid species (teleostei). | histochemical properties of intestine goblet cells in firemouth cichlid, zebra mbuna, freshwater angelfish and platyfish are described. goblet cells occurred regularly in the epithelial cell layer throughout the entire intestine, they were strongly coloured by alcian blue at ph 2.5. this colour got gradually weaker when the ph was reduced, but still after alcian blue at ph 0.2 these cells displayed a distinct blue colour. when the goblet cells were treated with periodic acid-schiff (pas), they d ... | 2010 | 19833368 |
| geography disentangles introgression from ancestral polymorphism in lake malawi cichlids. | phenotypically diverse lake malawi cichlids exhibit similar genomes. the extensive sharing of genetic polymorphism among forms has both intrigued and frustrated biologists trying to understand the nature of diversity in this and other rapidly evolving systems. shared polymorphism might result from hybridization and/or the retention of ancestrally polymorphic alleles. to examine these alternatives, we used new genomic tools to characterize genetic differentiation in widespread, geographically str ... | 2010 | 20149093 |
| intraspecific cone opsin expression variation in the cichlids of lake malawi. | the expression of cone opsin genes is a primary determinant of the characteristics of colour vision. interspecific variation in opsin expression is common in african cichlids. it is correlated with foraging among cichlids from lake malawi, and with ambient light environment among cichlids from lake victoria. in this study, we tested whether gene expression varied within species such that it might be important in contributing to divergence. we hypothesized that light attenuation with depth would ... | 2010 | 21091561 |
| female maylandia zebra prefer victorious males. | females of a widespread species of the rock-dwelling haplochromine cichlids of lake malawi, maylandia zebra, show preference for males that successfully evict intruding males from their territory. this behaviour, experimentally induced by the investigators in a laboratory setting, was also preferred over males that were not permitted to interact with any other individual. | 2011 | 21284646 |
| divergence in cis-regulatory sequences surrounding the opsin gene arrays of african cichlid fishes. | abstract: background: divergence within cis-regulatory sequences may contribute to the adaptive evolution of gene expression, but functional alleles in these regions are difficult to identify without abundant genomic resources. among african cichlid fishes, the differential expression of seven opsin genes has produced adaptive differences in visual sensitivity. quantitative genetic analysis suggests that cis-regulatory alleles near the sws2-lws opsins may contribute to this variation. here, we s ... | 2011 | 21554730 |