Aspects of the biology of the Australian Grayling Prototroctes maraena Günther (Pisces : Prototroctidae)

1978 ◽  
Vol 29 (6) ◽  
pp. 743 ◽  
Author(s):  
KA Bishop ◽  
JD Bell

The Australian grayling, P. maraena, is generally regarded as Australia's most endangered freshwater fish species. A sample of 312 specimens from the Shoalhaven River, N.S.W., provided data on various aspects of its biology. The sample showed a bimodal length frequency distribution of 1 + and 2+ fish aged by otoliths. Grayling appear to suffer severe mortality, possibly as a result of spawning at age 2. The spawning season in the Shoalhaven River was from early February to early March and available data suggest that grayling are anadromous. P. maraena is a microphagic omnivore, and stomachs sampled contained principally cladocerans, algae and small insects. The need for further research to elucidate the grayling's habitat requirements and to determine effective conservation measures is stressed.

2021 ◽  
Vol 9 ◽  
Author(s):  
Giovanni Negro ◽  
Stefano Fenoglio ◽  
Emanuele Quaranta ◽  
Claudio Comoglio ◽  
Isabella Garzia ◽  
...  

The MesoHABitat SImulation Model (MesoHABSIM) is the preferred method to calculate spatio-temporal variation in the fish habitat availability in Italian rivers. With the aim of improving the applicability of the MesoHABSIM approach in the Italian territory, we carried out a systematic review of physical habitat preferences for 31 freshwater fish species and three freshwater lampreys, representing 75% of the total indigenous freshwater fish community of Italy. Information related to suitable ranges of depth, flow velocity, biotic/abiotic substrates, covers/shelters was collected and summarized for two critical life stages (adult and juvenile) and two bioperiods (rearing/growth and spawning). Overall, 250 publications were reviewed, classified as 206 peer-reviewed papers, 20 books, 7 PhD thesis, and 17 grey literature sources. Our analysis revealed substantial deficits of information about habitat requirements for more than 30% of Italian freshwater fish species. This information is particularly scarce for the most threatened endemic species, especially for their most critical bioperiod (i.e., spawning). With the aim of preserving freshwater fish biodiversity as required in the EU Biodiversity Strategy for 2030 (European Commission, 2020), accurate information on physical habitat requirements for spawning is crucial. As an example application of MesoHABSIM, the collected habitat preference information was used to define and apply mesohabitat suitability criteria for one fish species (Telestes muticellus) in a regulated river reach of Argentina Creek (Province of Imperia, Italy). This analysis demonstrates the potential for applying information from the current review to other fish species.


2016 ◽  
Vol 5 (06) ◽  
pp. 4620
Author(s):  
Manal M. Khalifa ◽  
Ramadan A. S. Ali ◽  
Abdalla N. Elawad* ◽  
Mohammad El. ElMor

Age and growth characteristics of the thin-lipped Grey Mullet (Liza ramada) were investigated in Eastern coast of Libya. Aging was done by two methods: counting annuli on scales and by length frequency distribution, a total of 218 scales were studied for age determination, in addition of 334 fishes specimen for length frequency distribution reading. Four age groups were determined from scale reading, and five age groups from length frequency distribution methods, the parameters of the Von Bertalanffy growth equation for both sex of all individuals were estimated at 35.4 cm, 0.187 per year, -1.14 years and 2.4, for male were estimated at 35.7 cm, 0.17 per year, -1.367 and 2.3, for female were 38.6 cm, 0.156 per year, -1.383 and 2.4, for L∞, k and t0, and φ′, respectively.


Author(s):  
Sam Wenaas Perrin ◽  
Kim Magnus Bærum ◽  
Ingeborg Palm Helland ◽  
Anders Gravbrøt Finstad

Author(s):  
Maria João Costa ◽  
Gonçalo Duarte ◽  
Pedro Segurado ◽  
Paulo Branco

2007 ◽  
Vol 57 (4) ◽  
pp. 423-432 ◽  
Author(s):  
Evelien Maerten ◽  
Marcel Eens ◽  
Guy Knaepkens

AbstractAlthough small benthic freshwater fish species are an important biological component of fish assemblages and free instream movement is indispensable for their survival, they are often neglected in fish pass performance studies. In this study, a capture-mark-recapture approach was used to assess whether small bottom-dwelling species, including gudgeon (Gobio gobio), stone loach (Barbatula barbatula), spined loach (Cobitis taenia) and bullhead (Cottus gobio), were able to cross a pool-and-weir fish pass in a regulated lowland river. Some tagged individuals of stone loach (18%), gudgeon (7%) and spined loach (2%) managed to successfully ascend the fish pass under study, despite the fact that water velocity levels in the different overflows of the facility (between 0.55-1.22 m/s) exceeded the critical swimming speed of all three species. Although this suggests that a pool-and-weir fish pass is a able to facilitate upstream movement of some small benthic species in a regulated river, more detailed research incorporating advanced tagging and retrieving techniques is necessary.


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