Observations on the biology and seasonal variation in feeding of the east coast round herring Etrumeus wongratanai (Clupeiformes), off Scottburgh, KwaZulu‐Natal, South Africa

Abstract

The basic biology and ecology of the South African east coast round herring Etrumeus wongratanai was investigated from samples of fish collected between 2013 and 2016. This species is short‐lived and reaches a maximum of 3 years of age, with rapid growth in its first year of life. It reproduces from June to December (austral summer) and condition factor was lowest in May through to August and increased from September, probably reflecting the physiological strain before and during spawning. Fish larvae were the most important food items consumed during summer, whereas eucalanid copepods were the most important prey at other times of the year. Stable‐isotope data suggest that there are gradual changes in the trophic level with increasing fish size, δ15N and δ13C values also differed between seasons. The results obtained here are compared with those of other Etrumeus species, regionally and globally.

Ovarian dynamics, batch fecundity and spawning phenology of the lessepsian migrant Etrumeus golanii DiBattista, Randall & Bowen, 2012 (Clupeidae: Dussumieriinae)

“…In plots of monthly averages, an overall increasing trend was noted from winter to July, which appeared to be followed by an opposite, decreasing trend, especially in females. Similarly, in E. wongratanai off South Africa, the lowest somatic condition was observed between April and August (austral autumn to winter) and the condition increased between September and January (spring to summer) (Vorsatz et al, 2019). In the latter study, high interannual variability was also observed, occasionally masking the usual seasonal pattern.…”

“…Indeed, Osman et al (2013) observed that the diet of E. golanii included high quantities of fish larvae in summer, which these authors attributed to their increased abundance at that time of the year. High consumption of fish larvae in summer has also been reported for E. wongratanai off the east coast of South Africa (Vorsatz et al, 2019).…”

“…Spawning of the east African round herring Etrumeus wongratanai DiBattista, Bowen & Randall 2012 takes place from the onset of austral winter to early summer (Vorsatz et al, 2019). The peak spawning period of the Whitehead's (West African) round herring Etrumeus whiteheadi Wongratana 1983 occurs from August to October (austral winter/spring) and spawning takes place over a prolonged season (Roel & Melo, 1990).…”

Risk assessment of Golani’s round herring (Etrumeus golanii) in the Greek seas (northeastern Mediterranean Sea)

“…Estimates of economic losses in EU Member States are not yet assessed, while further studies are needed to be implemented in order to estimate the abundance of the species in Greek waters and to have sufficient for a holistic and correct assessment (Kourantidou et al, 2022). Until now, it is not known to which extent it functions territorially and competitively with commercial small pelagic species such as the European anchovy and European pilchard (Vorsatz et al, 2019). However, it does not appear to have negative impacts on these stocks and currently no population management practices are in place (Akyol and Ulas, 2016).…”

Ecomorphological relations of sympatric juveniles of Clupeiformes from a Brazilian sandy beach

“…Ecomorphology may be an important indicator of species diet and trophic position (Blasina et al, 2016), being able to identify adaptative convergence in phylogenetically distant species, and adaptative divergences in phylogenetically close ones (Reilly & Wainwright, 1994;Cassati & Castro, 2006). It helps classifying the feeding habits associated with linear models, identifying possible changes in species feeding patterns and trophic levels according to the phase of the life cycle and infer about swimming ability (Vorsatz et al, 2019;Souza & Pompeu, 2020;Podder et al, 2021a,b;Santos et al, 2021).…”