Topic
Serranochromis
About: Serranochromis is a research topic. Over the lifetime, 17 publications have been published within this topic receiving 252 citations.
Papers
TL;DR: Comparisons of population size structure and gonad condition during the falling water (May-August) and low water (SeptemberDecember) seasons indicated that the seven common Serranochromis initiate spawning near the end of the low water period.
Abstract: The Upper Zambezi River drainage of Zambia contains six Serranochromis species belonging to the largemouth, piscivorous subgenus Serranochromis and three smallmouth, invertebratefeeding species of the subgenus Sargochromis. A survey of the Barotse floodplain and associated drainages revealed that two species, S. (S.) /ongimanus (Boulenger) and S. (S.) thumbergi (Castelnau), were uncommon on the floodplain. S. thumbergi appeared to be more abundant in the Kafue, Chobe, and Kabompo rivers than the Upper Zambezi proper. Adults of the three largest species (i.e. S. (S.) robustus (Gunther), S. (S.) a/Ius (Winemiller & Kelso-Winemiller), and S. (Sar.) giardi (pellegrin)) inhabit the main channel of the Zambezi River during low water, whereas most adults of the other four species (i.e., S. (S.) macrocephalus (Boulenger), S. (S.) angusticeps (Boulenger), S. (Sar.) codringtoni (Boulenger), and S. (Sar.) car/ottae (Boulenger) were collected from lagoons, canals and backwaters. Comparisons of population size structure and gonad condition during the falling water (May-August) and low water (SeptemberDecember) seasons indicated that the seven common Serranochromis initiate spawning near the end of the low water period. Examination of gonad condition during the pre-spawning period indicated that Serranochromis attain maturity at the following sizes: S. robustus, males (275-300 mm S.L.), females (250275 mm); S. macrocephalus, both sexes (150-200 mm); S. a/tus, males (275-325 mm), females (250-300mm); S. angusticeps, males (2S0-275mm), females (175-225mm); S. giardi, males (275-300 mm), females (225-250 mm); S. codringtoni, males (150 mm), females (125-150 mm); S. car/ottae, males (150-175mm), females (100-125mm). Age was estimated from scale annuli comprised of closely spaced circuli that corresponded to the period of rising water (DecemberMarch). S. robustus. S. a/Ius. S. angusticeps, and S. giardi matured at approximately 3 years, and S. macrocephalus. S. codringtoni, and S. car/ottae matured at approximately 2 years in the Barotse floodplain. The average numbers of mature oocytes per female were as follows: S. robustus1165; S. macrocepha/us-810; S. a/tus-920; S. angusticeps-627; S. codringtoni-580; S. car/ottae-362. Fecundity exhibited a weak positive relationship with female size. Analysis of stomach contents showed that interspecific diet overlap was low among both immature and mature size classes of Serranochromis. Adult size classes of S. robustus fed primarily on small Synodontis catfishes, S. macrocephalus fed mostly on mormyrid and cichlid fishes, S. a/Ius specialized on mormyrids, ~nd S. angusticeps fed primarily on small cyprinid and characid fishes. The three members of the subgenus Sargochromis consumed mostly invertebrates. Molluscs were the most important item in the diet of S.giardi, and aquatic insects and fish scales were predominant in the diet ofS. car/DIrGe. Larger size classes of S. codringtoni consumed large amounts of seeds (Gramin'ac'eae). If habitat and 'diet are considered together, niche separation among Upper , Zambezi Serranochromis species appears to be nearly complete.
58 citations
TL;DR: Electrophoretic analysis of the loci, using aqueous extracts of brain, eye, gill, heart, kidney, liver, serum, stomach muscle, testis and white muscle, revealed the products of 40 loci for routine analysis and gene expression is similar among all species studied.
Abstract: Gene products of 40 loci in 15 species of the cichlid genera Chetia, Hemichromis, Oreochromis, Pharynogochromis, Serranochromis and Tilapia were examined by horizontal starch-gel and vertical polyacrylamide-gel electrophoresis. Electrophoretic analysis of the loci, using aqueous extracts of brain, eye, gill, heart, kidney, liver, serum, stomach muscle, testis and white muscle, revealed the products of 40 loci for routine analysis. Genetic variation within species was observed at 18 loci and average heterozygosities ranged between 0.021 and 0.047 which is less than previous estimates based on fewer loci and smaller sample sizes for the same species. Interspecific variation exists and can be used to identify the species studied. Gene expression is similar among all species studied.
42 citations
TL;DR: During a survey of fish ectoparasites in Lake Kariba (Zimbabwe), two crustaceans were often encountered and clear host preferences were shown, with seasonal variations of the prevalence occurred, the hot season being the less favourable.
Abstract: During a survey of fish ectoparasites in Lake Kariba (Zimbabwe), two crustaceans were often encountered. Dolops ranarum (Branchiura), parasite of the body, mouth and gill chamber, infected mostly cichlids, the catfish Clarias gariepinus, Synodontis zambezensis and two Mormyrids. Among cichlids clear host preferences were shown. No seasonal variations could be detected in the infections. D. ranarum parasitized predominantly fish above 15 cm in standard length. Lamproglena monodi (Copepoda) parasitized only the gills of cichlids with a preference for Serranochromis codringtonii, S. macrocephalus and Tilapia rendalli. Small fish were seldom infected. Seasonal variations of the prevalence occurred, the hot season being the less favourable. Few other crustaceans were found during the survey: a single specimen of Lamproglena hemprichii on the gills of the tigerfish, Hydrocynus vittatus; three specimens of Afrolernaea longicollis, one found on the gills of Hippopotamyrus discorhynchus and two on the gills of Mormyrops deliciosus; a hundred of Ergasilus mirabilis in a specimen of H. discorhynchus.
26 citations
TL;DR: The biogeographical history of Cichlidae across the Zambezi- Congo watershed is not only key to cichlid biogeography on an African scale, but also complementary toBiogeography of all other teleosts in the region.
Abstract: Fishes normally restricted to inland waters are valuable model systems for historical biogeography, inter alia, because of their limited dispersal abilities and concordance with the distribution patterns of other freshwater taxa (Zogaris et al. 2009). The comparison of fish species assemblages has been the major biogeographical tool for delineating African aquatic ecoregions as the fossil record is often meagre and merely offers complementary information. This is, for example, the case for the Zambezian and Congolian ichthyofaunal provinces, which display substantial contemporary fish diversity (Stewart 2001). Between both regions lies the Bangweulu-Mweru ecoregion (sensu Scott 2005), known for its high percentage of endemicity. Although hydrographically belonging to the Congo Basin, the Bangweulu-Mweru ecoregion has a high affinity with the Zambezi province (Scott 2005), due to historical river connections (Tweddle 2010). Studies comparing the Zambezi and Congo ichthyofaunal provinces are rare and hampered by lack of data from the Congo Basin. The latter harbours more than 1250 fish species (Snoeks et al. 2011) while in the Zambezi, only 120 freshwater fishes are found (Tweddle 2010). Indeed, species richness declines in all major African teleost families from the Congo Basin southwards, riverine haplochromine cichlids forming a notable exception to this rule (Joyce et al. 2005). Although it was hypothesized by Tweddle (2010) that the origin of many Zambezian fish species is in the Congo Basin, the haplochromines Serranochromis Regan, Sargochromis Regan, Pharyngochromis Greenwood and Chetia Trewavas, together forming the serranochromines, have their centre of diversity in the rivers of the Zambezian ichthyofaunal province (Joyce et al. 2005). Therefore, the biogeographical history of Cichlidae across the Zambezi- Congo watershed is not only key to cichlid biogeography on an African scale, but also complementary to biogeography of all other teleosts in the region. Yet, colonisation and speciation patterns are difficult to unravel due to complex hydrological history (Katongo et al. 2007; Schwarzer et al. 2012).
26 citations
TL;DR: In this paper, a pilot study was conducted to assess whether and how telemetry can be used to follow the movements of larger cichlids in the upper Zambezi River and study the movements, habitat preferences and homing behavior of three cichlsid species important for subsistence and trophy fishing during a period of increasing water flow towards the rainy period.
Abstract: – During 5–7 October 1999, 16 cichlids (30.5–51.0 cm) were tagged with radio transmitters in the Zambezi River in Namibia (eight threespot tilapia Oreochromis andersonii, seven pink happy Sargochromis giardi and one humpback largemouth Serranochromis altus). The main objectives of this pilot study were 1) to assess whether and how telemetry can be used to follow the movements of larger cichlids in the upper Zambezi River and 2) to study the movements, habitat preferences and homing behavior of three cichlid species important for subsistence and trophy fishing during a period of increasing water flow towards the rainy period. Nine fish showed a downriver movement immediately after release, believed to be a behavioral response to catch and tagging. From 11 October, only small-scale movements were recorded. Average total distance moved from 11 October to 1 March was 375 m (range=1–1150) for threespot tilapia and 1276 m (range=540–1990) for pink happy. The farthest position compared to the position held on 11 October was on average 220 m away (range=0–500) for threespot tilapia and 538 m (range=20–1500) for pink happy. Displaced individuals did not show homing to the catch site. The threespot tilapia were, on average, located in the main river during 67% of the tracking surveys, in backwaters during 13% and in mouth of backwaters during 20%. The pink happy were, on average, located in the main river during 71% of the tracking surveys, in backwaters during 25% and in mouth of backwaters during 4%.
23 citations
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Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2015 | 2 |
| 2013 | 2 |
| 2012 | 1 |
| 2009 | 1 |
| 2001 | 1 |