scholarly journals Astiotrema turneri n. sp. (Digenea: Plagiorchiidae) from cichlid fishes (Cichlidae: Perciformes) of Lake Malawi, south-eastern Africa

Zootaxa ◽  
2006 ◽  
Vol 1319 (1) ◽  
pp. 43 ◽  
Author(s):  
RODNEY A. BRAY ◽  
COCK VAN OOSTERHOUT ◽  
JONATAN BLAIS ◽  
JOANNE CABLE
Keyword(s):  
Ventral Sucker ◽  
Body Shape ◽  
Lake Malawi ◽  
Eastern Africa ◽  
Intestinal Bifurcation ◽  
Cichlid Species ◽  
Cichlid Fishes ◽  
South Eastern

Astiotrema turneri n. sp. is described from the cichlid species Pseudotropheus zebra, P. emmiltos, Labeotropheus trewavasae and Melanochromis vermivorus from Lake Malawi. It differs from Astiotrema reniferum (as described by Yeh & Fotedar 1958) in its distinctly broader body, the much smaller cirrus-sac, its oblique testes, the shorter ventral sucker to ovary distance, the vitellarium reaching into the forebody and the extracaecal uterus; from Astiotrema impletum in the sucker-ratio, the longer caeca, the smaller cirrus-sac and the extracaecal uterus; and from Glossidium pedatum (and its probable synonyms Astiotrema lazeri and Afromacroderoides lazerae) in its much broader body shape, in its distinct oesophagus, the intestinal bifurcation in the posterior forebody, in the distinctly oblique testes, the extracaecal uterus and the vitellarium reaching well into the forebody.

scholarly journals Genetic basis of body shape variation along the benthic-pelagic axis in cichlid fishes

2021 ◽  
Author(s):  
Leah DeLorenzo ◽  
Destiny Mathews ◽  
A. Allyson Brandon ◽  
Mansi Joglekar ◽  
Aldo Carmona Baez ◽  
...  
Keyword(s):  
Adaptive Radiation ◽  
Body Shape ◽  
Genetic Basis ◽  
Molecular Mechanisms ◽  
Lake Malawi ◽  
Shape Variation ◽  
East African ◽  
Cichlid Fishes ◽  
African Rift ◽  
Two Hybrid

Divergence along the benthic-pelagic axis is one of the most widespread and repeated patterns of morphological variation in fishes, producing body shape diversity associated with ecology and swimming mechanics. This ecological shift is also the first stage of the explosive adaptive radiation of cichlid fishes in the East African Rift Lakes. We use two hybrid crosses of cichlids (Metriaclima sp. x Aulonocara sp. and Labidochromis sp. x Labeotropheus sp., >975 animals total) along the benthic-pelagic ecomorphological axis to determine the genetic basis of body shape diversification. Using a series of both linear and geometric shape measurements, we identify 55 quantitative trait loci (QTL) that underlie various aspects of body shape variation associated with benthic-pelagic divergence. These QTL are spread throughout the genome, each explain 3.0-7.2% of phenotypic variation, and are largely modular. Further, QTL are distinct both between these two crosses of Lake Malawi cichlids and compared to previously identified QTL for body shape in fishes such as sticklebacks. We find that body shape is controlled by many genes of small effects. In all, we find that convergent benthic and pelagic body phenotypes commonly observed across fish clades are most likely due to distinct genetic and molecular mechanisms.

scholarly journals Mapping epigenetic divergence in the massive radiation of Lake Malawi cichlid fishes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Grégoire Vernaz ◽  
Milan Malinsky ◽  
Hannes Svardal ◽  
Mingliu Du ◽  
Alexandra M. Tyers ◽  
...  
Keyword(s):  
Phenotypic Diversity ◽  
Sequence Divergence ◽  
Lake Malawi ◽  
Cichlid Species ◽  
Adaptive Diversification ◽  
Cichlid Fishes ◽  
Muscle Tissues ◽  
Genome Wide ◽  
Dietary Ecology ◽  
Species Specific

AbstractEpigenetic variation modulates gene expression and can be heritable. However, knowledge of the contribution of epigenetic divergence to adaptive diversification in nature remains limited. The massive evolutionary radiation of Lake Malawi cichlid fishes displaying extensive phenotypic diversity despite extremely low sequence divergence is an excellent system to study the epigenomic contribution to adaptation. Here, we present a comparative genome-wide methylome and transcriptome study, focussing on liver and muscle tissues in phenotypically divergent cichlid species. In both tissues we find substantial methylome divergence among species. Differentially methylated regions (DMR), enriched in evolutionary young transposons, are associated with transcription changes of ecologically-relevant genes related to energy expenditure and lipid metabolism, pointing to a link between dietary ecology and methylome divergence. Unexpectedly, half of all species-specific DMRs are shared across tissues and are enriched in developmental genes, likely reflecting distinct epigenetic developmental programmes. Our study reveals substantial methylome divergence in closely-related cichlid fishes and represents a resource to study the role of epigenetics in species diversification.

Body shape variation in relation to resource partitioning within cichlid trophic guilds coexisting along the rocky shore of Lake Malawi

2003 ◽  
Vol 53 (1) ◽  
pp. 59-70 ◽  
Author(s):  
Daud Kassam ◽  
Kosaku Yamaoka ◽  
Aggrey Ambali ◽  
Dean Adams
Keyword(s):  
Resource Partitioning ◽  
Body Shape ◽  
Lake Malawi ◽  
Rocky Shores ◽  
Shape Variation ◽  
Cichlid Species ◽  
Body Design ◽  
Ctenopharynx Pictus ◽  
Temporal Dimensions

AbstractTo appreciate better how cichlids segregate along the trophic, spatial and temporal dimensions, it is necessary to understand the cichlids' body design, and its role in resource partitioning. We investigated body shape variation, quantified using landmark-based geometric morphometrics, among cichlid species belonging to algal and zooplankton feeders coexisting along the rocky shores of Lake Malawi, in order to elucidate the adaptive significance of body shape. Significant differences were found within zooplankton feeders in which Copadichromis borleyi had a shorter gape, smaller eyes and shorter caudal peduncle relative to Ctenopharynx pictus and, within algal feeders, Labeotropheus fuelleborni had a shorter and inferior subterminal gape, and shorter head relative to Petrotilapia genalutea. Variation among species is discussed with reference to trophic and feeding microhabitat differentiation which enables us to appreciate the role of body shape in enhancing ecological separation, and thus leads to coexistence among cichlid species.

scholarly journals Gene coexpression networks reveal molecular interactions underlying cichlid jaw modularity

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Pooja Singh ◽  
Ehsan Pashay Ahi ◽  
Christian Sturmbauer
Keyword(s):  
In Silico ◽  
Regulatory Networks ◽  
Evolutionary Significance ◽  
Cichlid Species ◽  
Cichlid Fishes ◽  
Gene Coexpression ◽  
Modular Evolution ◽  
Jaw Apparatus ◽  
Coexpression Networks ◽  
Pharyngeal Jaw

Abstract Background The oral and pharyngeal jaw of cichlid fishes are a classic example of evolutionary modularity as their functional decoupling boosted trophic diversification and contributed to the success of cichlid adaptive radiations. Most studies until now have focused on the functional, morphological, or genetic aspects of cichlid jaw modularity. Here we extend this concept to include transcriptional modularity by sequencing whole transcriptomes of the two jaws and comparing their gene coexpression networks. Results We show that transcriptional decoupling of gene expression underlies the functional decoupling of cichlid oral and pharyngeal jaw apparatus and the two units are evolving independently in recently diverged cichlid species from Lake Tanganyika. Oral and pharyngeal jaw coexpression networks reflect the common origin of the jaw regulatory program as there is high preservation of gene coexpression modules between the two sets of jaws. However, there is substantial rewiring of genetic architecture within those modules. We define a global jaw coexpression network and highlight jaw-specific and species-specific modules within it. Furthermore, we annotate a comprehensive in silico gene regulatory network linking the Wnt and AHR signalling pathways to jaw morphogenesis and response to environmental cues, respectively. Components of these pathways are significantly differentially expressed between the oral and pharyngeal jaw apparatus. Conclusion This study describes the concerted expression of many genes in cichlid oral and pharyngeal jaw apparatus at the onset of the independent life of cichlid fishes. Our findings suggest that – on the basis of an ancestral gill arch network—transcriptional rewiring may have driven the modular evolution of the oral and pharyngeal jaws, highlighting the evolutionary significance of gene network reuse. The gene coexpression and in silico regulatory networks presented here are intended as resource for future studies on the genetics of vertebrate jaw morphogenesis and trophic adaptation.

Extensive MHC variability in cichlid fishes of Lake Malawi

Nature ◽  
1993 ◽  
Vol 364 (6435) ◽  
pp. 330-334 ◽  
Author(s):  
Dagmar Klein ◽  
Hideki Ono ◽  
Colm O'hUigin ◽  
Vladimir Vincek ◽  
Tijs Goldschmidt ◽  
...  
Keyword(s):  
Lake Malawi ◽  
Cichlid Fishes

Xenosellidae, a new family of Janiroidea (Asellota: Isopoda:  Crustacea), for Xenosella coxospinosa gen. nov., sp. nov.,  from the marine bathyal of eastern Australia

Zootaxa ◽  
2005 ◽  
Vol 1085 (1) ◽  
pp. 21 ◽  
Author(s):  
JEAN JUST
Keyword(s):  
New Species ◽  
Body Shape ◽  
New Genus ◽  
New Genus And Species ◽  
South Eastern ◽  
Incertae Sedis ◽  
New Family ◽  
Eastern Australia ◽  
Similar Body ◽  
South Eastern Australia

A new genus and species of janiroidean Asellota, Xenosella coxospinosa, is described from the mid-bathyal slope off the coast of south-eastern Australia. Following a comparison of the new species to several families of broadly similar body shape, with emphasis on monotypic Pleurocopidae, a new family, Xenosellidae, is proposed for the new species. In the course of comparing relevant taxa, the current placements of Prethura Kensley in the Santiidae and Salvatiella Müller in the Munnidae are rejected. The two genera are considered to be incertae sedis within the Asellota superfamily Janiroidea pending further studies.

scholarly journals Hematospermia in a returned traveler

2017 ◽  
Vol 11 (1-2) ◽  
pp. 41 ◽  
Author(s):  
Raynell Lang ◽  
Jessica Minion ◽  
Alexander Wong
Keyword(s):  
Schistosoma Haematobium ◽  
Microscopic Analysis ◽  
Lake Malawi ◽  
Clinical Suspicion ◽  
Eastern Africa ◽  
Rare Presentation ◽  
Sexually Transmitted ◽  
Common Complaint ◽  
High Clinical Suspicion ◽  
Global Travel

Hematospermia is a common complaint among patients seen in outpatient urology clinics. The differential diagnosis is broad and includes inflammatory, infectious, neoplastic, structural, systemic, and traumatic causes. The most common infectious causes are uropathogens and sexually transmitted infections. However, with increasing global travel, physicians must maintain a high clinical suspicion for pathogens not endemic to their region, including Echinococcus, Mycobacterium tuberculosis, and Schistosoma.1 We present a case of hematospermia in a traveler returning from Eastern Africa with exposure to Lake Malawi. The patient’s microscopic analysis of semen was positive for Schistosoma haematobium, revealing a rare presentation of S. haematobium infection.

Pelagic Cichlid Fishes of Lake Malawi/Nyasa: Biology, Management and Conservation

2007 ◽  
pp. 353-366 ◽  
Author(s):  
G. F. Turner ◽  
R. L. Robinson ◽  
B. P. Ngatunga ◽  
P. W. Shaw ◽  
G. R. Carvalho
Keyword(s):  
Lake Malawi ◽  
Cichlid Fishes ◽  
Management And Conservation
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