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An ecological shift has populated Engraulicypris sardella as a livelihood and economic drive among fishers in Malawi. However, the paucity of biological information regarding E. sardella limits the effective monitoring and sustainable management of the fishery. This has created a heavily invested fishery in terms of the effort put into fishing, but it is poorly managed. Moreover, the current production capacity from the fishery has a negligible impact on lessening the shortfall of the national fish demand, indicating its underperformance. Therefore, the productive efficiency of Lake Malawi Chilimira fishers in exploiting E. sardella was analysed. A multi-stage sampling technique was used to sample 355 Chilimira fishers between July and October 2021. Results from the translog stochastic frontier model revealed that Chilimira fishers had an overall mean technical efficiency of 60% that ranged between 21% and 92%. This indicates that Chilimira fishers are 40% technically inefficient in exploiting E. sardella. The fishing inputs of bunt area, light emitting diode (LED) bulbs, and mesh size significantly contributed to technical efficiency, whereas boat size, fishing depth, number of hauls, and mosquito net lining significantly reduced the technical inefficiency. On average, the Chilimira fishery is operating with increasing returns to scale with bunt area, the quantity of fuel (litres), and the number of LED bulbs having positive input–output elasticity. This means that new developments in the fishery, including LED bulbs, increased bunt area, and boat size, are key factors that will improve fishing efficiency for sustainable fishery exploitation. In contrast, illegal fishing units of small bunt mesh size and mosquito net lining at the bunt threaten the sustainability of the fishery. It is, therefore, important that relevant stakeholders put policy measures in place that promote sustainable fishing effort approaches in exploiting the virgin offshore fishery to maximise catch.

Ligula intestinalis is a tapeworm using copepods and cyprinid fish as intermediate hosts and fish-eating birds as final hosts. Since some parasites can increase their own fitness by manipulating the behavior of the intermediate host, we explored if this parasite affected predator avoidance, swimming activity and depth preference of the fish intermediate host, Engraulicypris sardella. We found that when L. intestinalis had reached a developmental stage that is able to establish in the bird host, it had a significant impact on E. sardella behavior, while the tapeworm that was not fully developed had little effect and fish hosts showed a behavior more similar to uninfected fish. These results are discussed with respect to two different processes: the manipulation hypothesis and the energy drain hypothesis.

Evolutionary theory predicts that infection by a parasite that reduces future host survival or fecundity should select for increased investment in current reproduction. In this study we use the cestode Ligula intestinalis and its intermediate fish host Engraulicypris sardella in Wissman Bay, Lake Nyasa (Tanzania) as a model system. Using data about infection of E. sardella fish hosts by L. intestinalis collected for a period of 10 years, we explored whether parasite infection affects the fecundity of the fish host E. sardella, and whether host reproductive investment has increased at the expense of somatic growth. We found that L. intestinalis had a strong negative effect on the fecundity of its intermediate fish host. For the non-infected fish we observed an increase in relative gonadal weight at maturity over the study period, while size at maturity decreased. These findings suggest that the life history of E. sardella has been shifting towards earlier reproduction. Further studies are warranted to assess whether these changes reflect plastic or evolutionary responses. We also discuss the interaction between parasite and fishery-mediated selection as a possible explanation for the decline of E. sardella stock in the lake. KEYWORDS Life history evolution; African Great Lakes; Lake Nyasa; Usipa; Lake Malawi sardine; Parasite invasion; Environmental change.

Lake Malawi continues experiencing serious depletion of most valuable fish species. Presently, commercial and artisanal fishery are forced to target less valuable fish species. Evidently, economic importance of Engraulicypris sardella in Malawi cannot be negated as it currently contributes over 70% of the total annual landings. However, such highest contribution could be a sign of harvesting pressure. Therefore, as the species continues being increasingly exploited, the development of scientific understanding through application of stochastic models is particularly relevant for present and future policy making and formulation of strategies to sustain the resource in the lake. Thus, the study was designed to forecast the annual catch trend of E. sardella from Lake Malawi. The study used time series data from 1976 to 2015 period obtained from Monkey Bay Fisheries Research Station of the Malawi Fisheries Department. The study adopted Box-Jenkins procedures to identify appropriate Autoregressive Integrated Moving Average (ARIMA) model, estimate parameters in ARIMA model and conducting diagnostic check. The study findings showed that ARIMA (2,1,1) model had least Normalized Bayesian Information Criterion (NBIC) value making it a appropriate model for the study. ARIMA (2,1,1) model showed that E. sardella annual catches are positively fluctuating. Again, the model predicted that E. sardella annual catches from Lake Malawi will increase from the annual total landings of 71,778.47 metric tons to 104,261.20 metric tons in the next 10 years (ceteris paribus). Key words: Box-Jenkins, Engraulicypris sardella, Lake Malawi, autoregressive integrated moving average (ARIMA), Modelling, Usipa, Stochastic.

The hatching period and the growth of Malawian cyprinid Engraulicypris sardella larvae and juveniles collected from two sites along the southwestern shoreline of Lake Malawi were investigated using otolith increment information. The lapillus was used to determine the age in days following previous studies. The hatching months of fish estimated on the basis of lapillus increment counts were from November to July (nine months of a year), demonstrating that this species had an extended spawning season. Based on the age analysis, the fish were separated into two hatching groups: fish that hatched in the rainy season and those that hatched in the dry season. The growth rate of the former (0.70 mm TL per day) was significantly higher than the latter (0.52 mm TL per day). This growth difference was considered to be due to water temperature in the lake.Keywords: Engraulicypris sardella larvae and juveniles, lapillus increments, growth, spawning season, Lake Malawi

Features and increments of otoliths in Engraulicypris sardella were observed. The sagitta was arrowhead shaped with an obvious core and rostra, the latter being fragile and easily destroyed by extracting and grinding processes. Increments around the core were readable but not in rostra. The lapillus was round fan-shaped with an obvious core. Increments in the lapillus were clearly deposited from the core to the margin. The asteriscus had an ambiguous core that led to difficulty in discerning the first increment and had fewer increments than the lapilli. Thus, the lapillus is the most appropriate for reading otolith increments.

Fish parasites have diverse ecological impacts on fish populations and are presently becoming useful as bio-indicators of fish migration and feeding. Studies of fish parasite in Lake Malawi severely lag behind the strides made in eco-evolutionary studies of its ichthyofauna. Over a period of eleven months from April 2003, we examined more than 1300 Engraulicypris sardella from Lake Malawi for cestode parasites. About 54 % of the fish had infections of between one and eight Ligula intestinalis plerocercoids. The infection occurred throughout the study period (mean prevalence 59 ±13%) but was most prevalent in December and June and was least prevalent in April. The majority of the hosts (78%) had a light parasite burden (one or two). Parasite prevalence increased with age of the fish. Prevalence and infection intensity oscillated closely with periods of peak abundance of zooplankton, the main food of E. sardella and intermediate hosts (copepods) of L. intestinalis. Increased exposure to the parasite with age aggravated by an ontogenetic diet shift from phytoplanktivory to zooplanktivory may be interacting with fluctuations in zooplankton production in driving the trophic transmission patterns of L. intestinalis in this ecosystem.Keywords: Engraulicypris sardella; Ligula intestinalis; trophic transmission; Lake Malawi

Artisanal fisheries yielded about 25% of the total fish landings and employed over 90% of all fishers worldwide in the early 1990s. Catch and effort trends of these fisheries are often difficult to monitor due to remote locations, the presence of multiple species in the catch, widely dispersed fishing, and a lack of resources available to fisheries managers. Traditional fishery practices and local knowledge of fish identification and ecology can provide convenient and cost-effective methods for monitoring artisanal fisheries. The open-water seine-net (“chirimila”) fishery of Chembe village in Lake Malaŵi National Park, Malaŵi, Africa, was monitored with methods based on local fish measurement and preservation and identification practices. The catch per unit effort, fishing effort, total catch, species composition, and bycatch of this artisanal fishery were determined for a 1-year period with these methods. The Chembe open-water seine-net fishery targets the small cyprinid Engraulicypris sardella ...

The present study analyses the length frequency distribution and total length-weight relationship of Engraulicypris sardella, a Cyprinidae fish endemic to Lake Niassa and the most caught in the lake. Fish were sampled from January to December 2012 through artisanal catches landing at Metangula. Results indicate that the total length (cm) from 1,449 specimens varies from 1.5 to 12.5 cm and the average was 9.26 cm ± 2.47. Engraulicypris sardella exhibited recruitment between August to December. The lengthweight relationship is expressed as the following equation P(g) = 0.00497*CT(cm)3.12 and suggests the isometric growth in this species. Further studies about length, growth and abundance were recommended Published

An empirical model relating food requirements to morphometric indices of metabolic rate was used to calculate consumption/biomass ratios (Q/B) for 16 species of fish that make the pelagic fish community in Lake Malawi/Niassa. The Q/B/year varied from 3.31 to 9.82, with the large catfish (Dinotopterus nyasensis) having the lowest and a small cyprinid (Engraulicypris sardella) having the highest Q/B ratio. Direct estimates of Q/B for four of the most abundant species, based on analysis of diel feeding patterns, ranged from 4.20 to 24.70; the extreme values in this range representing replicate studies on the same species, the predatory cichlid Rhamphochromis longiceps. Previous studies that indicated exceptionally low Q/B ratios (1.0) in pelagic cichlids from Lake Malawi are not supported by this more recent work.