Cytological and morphological ontogenesis and involution of the thymus in cichlid fishes (Cichlidae, Teleostei)

1995 ◽  
Vol 223 (2) ◽  
pp. 175-190 ◽  
Author(s):  
Lev Fishelson
Keyword(s):  
Cichlid Fishes

Biology of Crassicutis cichlasomae, a parasite of cichlid fishes in Mexico and Central America

1995 ◽  
Vol 69 (1) ◽  
pp. 69-75 ◽  
Author(s):  
T. Scholz ◽  
M.C.F. Pech-Ek ◽  
R. Rodriguez-Canul
Keyword(s):  
Central America ◽  
Developmental Stages ◽  
Infected Fish ◽  
Constant Darkness ◽  
Intermediate Hosts ◽  
Cichlid Fishes ◽  
Feeding Experiments ◽  
Light Darkness ◽  
Higher Temperature ◽  
Cichlasoma Urophthalmus

AbstractField study on the biology of Crassicutis cichlasomae Manter, 1936 (Digenea: Homalometridae) was carried out in a small swamp in a limestone factory near Mérida, Yucatán, Mexico. Aquatic snails, Littorina (Littoridinopsis) angulifera, harbouring C. cichlasomae rediae, cercariae and metacercariae, served both as the first and second intermediate hosts. Feeding experiments confirmed the conspecificity of metacercariae from naturally infected snails with adults from naturally infected fish. Gravid C. cichlasomae worms were obtained from experimentally infected fish 19 days post exposure at 22–24°C. Examination of fish from the swamp in Mitza and other localities in the Yucatan Peninsula showed that the cichlids Cichlasoma urophthalmus and C. meeki were definitive hosts of C. cichlasomae. There was no pronounced preference of C. cichlasomae adults for the site of their location in the intestine of the definitive host; a slightly higher proportion (41%) of worms was only found in the anterior third of the gut. The time of miracidium development varied from 18.5 to 27.5 days; different temperature (20.1–35.7°C) or light/darkness regimes influenced only slightly the rate of embryonic development, with shorter development times at higher temperature (34.8–35.7°C) and constant darkness and/or light. With the exception of the sporocyst, all developmental stages are described and figured.

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.

Positive selection of the long-wavelength opsin gene in South American cichlid fishes

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Thomaz Mansini Carrenho Fabrin ◽  
Luciano Seraphim Gasques ◽  
Rodrigo Junio da Graça ◽  
Sônia Maria Alves Pinto Prioli ◽  
Weferson Júnio da Graça ◽  
...  
Keyword(s):  
Positive Selection ◽  
Opsin Gene ◽  
South American ◽  
Long Wavelength ◽  
Cichlid Fishes ◽  
Selection Of

An adaptive series of protractile jaws in Cichlid fishes

1943 ◽  
Vol 72 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Theodore H. Eaton
Keyword(s):  
Cichlid Fishes

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

Evaluating the use of ram and suction during prey capture by cichlid fishes

2001 ◽  
Vol 204 (17) ◽  
pp. 3039-3051 ◽  
Author(s):  
Peter C. Wainwright ◽  
Lara A. Ferry-Graham ◽  
Thomas B. Waltzek ◽  
Andrew M. Carroll ◽  
C. Darrin Hulsey ◽  
...  
Keyword(s):  
Poecilia Reticulata ◽  
Prey Capture ◽  
Suction Feeding ◽  
Predator Species ◽  
Cichlid Fishes ◽  
Major Constraint ◽  
Exponential Decline ◽  
Astronotus Ocellatus ◽  
Limited Variation ◽  
Jaw Protrusion

SUMMARYWe characterized prey-capture strategies in seven species of cichlid fishes representing diverse trophic habits and anticipated feeding abilities. The species examined were Petenia splendida, Cichla ocellaris, Cichlasoma minckleyi, Astronotus ocellatus, Crenicichla geayi, Heros severus (formerly Cichlasoma severum) and Cyprichromis leptosoma. Three individuals per species were filmed with video at 500Hz as they captured live adult Artemia sp. and Poecilia reticulata. For each feeding sequence, we measured the contribution of predator movement towards the prey (i.e. ram) and the movement of prey towards the predator due to suction. The use of ram differed significantly among prey types and predator species, varying as much as sixfold across predator species. High values of ram resulted in high attack velocities. Jaw protrusion contributed as much as 50% to overall ram values in some species, verifying its role in enhancing attack velocity. Suction distance did not vary significantly among species. Diversity in prey-capture behavior was therefore found to reflect differences among species in the strategy used to approach prey. Limited variation in the distance from which prey were sucked into the mouth is interpreted as the result of an expected exponential decline in water velocity with distance from the mouth of the suction-feeding predator. We propose that this relationship represents a major constraint on the distance over which suction feeding is effective for all aquatic-feeding predators.

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