Beata Więcaszek

Palaemon elegans Rathke, 1837 in the food of Baltic cod (Gadus morhua callarias L., 1758) from the Gulf of Gdańsk

Abstract Analysis of stomach contents of 52 cod (Gadus morhua callarias) individuals (TL 37.0–58.0 cm) caught in November 2003 in the coastal waters of the Gulf of Gdańsk showed the presence of the prawn Palaemon elegans, a malacostracan species that has been recently reported as abundant in various parts of the Baltic Sea. This is the first observation of P. elegans as a cod food item in the Baltic Sea. The prawns were found in 88.5% of the stomachs analysed, accounting for 17% and almost 7% of food weight of cod <45.0 cm and ≥45.0 cm, respectively. The prawns consumed by the cod measured from 20 to 48 mm (average±SD: 31.7±5.3 mm), the prawn length increasing slightly with the cod length. Although P. elegans seems to be the most important invertebrate food item, diet in the cod was still dominated by fish. Neogobius melanostomus and Zoarces viviparus were the most important fish species found in the cod stomachs examined. In addition, the contents of some of the cod stomachs featured other malacostracan species, mainly Crangon crangon, as well as other invertebrates; however, these were of lesser importance. The significance of P. elegans as food of the cod fished commercially in the coastal waters of the Gulf of Gdańsk in comparison with other species preyed upon by cod there is discussed.

Morphological and molecular characterization of Ceratomyxa gurnardi sp. n. (Myxozoa: Ceratomyxidae) infecting the gallbladder of the grey gurnard Eutrigla gurnardus (L.) (Scorpaeniformes, Triglidae)

The myxosporean specimens were noted in grey gurnard Eutrigla gurnardus (L.) from the area near the Shetland Islands. The structure and dimensions of its vegetative stage differ from earlier descriptions. A sequence of small subunit ribosomal RNA gene obtained during the current study differs from other Ceratomyxa spp. available in GenBank. A phylogenetic position of parasite based on the 18S rDNA fragment was estimated. The proposed name for this myxosporean is Ceratomyxa gurnardi sp. n.

ASIAN PANGASIIDS-AN EMERGING PROBLEM FOR EUROPEAN INLAND WATERS? SYSTEMATIC AND PARASITOLOGICAL ASPECTS

Some species of the pangasiid catfishes are economically very important and have a large culture potential. They have been successfully bred and cultured in Thailand and Vietnam (Lerssutthichawal et al. 1999), from where they are exported to the European and American markets, processed mainly into fillets. Those fish, commonly referred to as “panga”, have hitherto been unknown to Europe and the USA. The most valuable catfish species are: sutchi catfish, Pangasianodon hypophthalmus (Sauvage, 1878), and basa, Pangasius bocourti Sauvage, 1880, which can be raised in the river-based cages or earth-constructed ponds. Their hybrids are also of high economical value (Hung et al. 2003). Pangasiids were also experimentally cultured in Puerto Rico during 2003–2004. They were successfully reproduced and cultured with results similar to those achieved in Asian aquaculture (McGee 2005). Moreover, Pangasius sp. is regarded as a new species for aquaculture (however not new to market or consumers) in central and eastern Europe (Varadi 2008). It is anticipated that in the next 5 years worldwide aquaculture production of Pangasius sp. could be similar to that achieved with tilapia and salmon (McGee 2005). ACTA ICHTHYOLOGICA ET PISCATORIA (2009) 39 (2): 131–138 DOI: 10.3750/AIP2009.39.2.08

ANALYSIS OF POPULATION AND TAXONOMICAL STRUCTURE OF ATLANTIC COD, GADUS MORHUA(ACTINOPTERYGII: GADIFORMES: GADIDAE) FROM THE BALTIC SEA WITH USE OF MICROSATELLITE DNA

A substantial decline in biomass of the Atlantic cod, Gadus morhua L., 1758, populations has been observed in recent decades. It might be related to overfishing and climate changes, as there has been an increase of average surface water temperature in some areas (e.g., North Sea) (Hutchinson et al. 2003). Since 1999, a plan for a longterm management of the cod stocks in the North Atlantic has been implemented by the EU and other countries. The plan was intended to reduce the fishing activity to sustain biological limits and to ensure spawning biomass for each stock. Twenty-seven main stocks of cod were recognized in the North Atlantic (Marteinsdottir et al. 2005). Evolutionary effects of cod fisheries were documented using eco-genetic models (Eikeset et al. 2005). These effects are yet to be studied and understood in wild populations with the application of a variety of genetic and molecular markers. Comprehensive understanding of population structure contributes to proper conservation of genetic resources. The extremely high fecundity of cod may cause non-equilibrium behaviour in genetic structure at certain levels (Arnason et al. 2004). Large scale geographic differentiation of the north eastern and north western Atlantic Ocean cod populations were ascertained by allozyme analysis and nuclear restriction fragment length polymorphism (RFLP) of anonymous cDNA loci (Mork et al. 1985, Pogson et al. 1995) and by studies of allele frequencies at pantophysin I locus (Case et al. 2005). Geographic differentiation on smaller scale, i.e., within eastern or western Atlantic populations were found most successfully at the blood protein loci (Dahle and Jorstad 1993), pantophysin I alleles (Case et al. 2005), ACTA ICHTHYOLOGICA ET PISCATORIA (2011) 41 (4): 307–314 DOI: 10.3750/AIP2011.41.4.07

Meristic and morphometric characters of small sandeel, Ammodytes tobianus L. (Actinopterygii: Ammodytidae), from the Gulf of Gdańsk, Baltic Sea

Small (or lesser) sandeel, Ammodytes tobianus L., is an inshore fish, found associated with sand and fine gravel banks up to, and including, the intertidal zone. It also occurs in estuaries (O’Connel and Fives 1995). The geographical distribution of A. tobianus ranges from the Murman Sea to the west coast of Iceland in the north, to the Baltic Sea in the east, and to Spain to the south. In the Mediterranean, it has been recorded from the Balearic Islands (Whitehead et al. 1986). Small sandeel used to be a common fish in the Baltic Sea. In 1998, a Polish fisheries survey, carried out in two naturally varying basins of the southern Baltic Sea (Poland), ACTA ICHTHYOLOGICA ET PISCATORIA (2007) 37 (1): 37–45

Checklist of the pathogens of lamprey species of Poland

Checklist of the pathogens of lamprey species of Poland This is a checklist of 51 pathogens of lamprey species found in Poland, including European river lamprey Lampetra fluviatilis (Linnaeus, 1758), European brook lamprey Lampetra planeri (Bloch, 1784), Ukrainian brook lamprey Eudontomyzon mariae (Berg, 1931), Danubian brook lamprey Eudontomyzon vladykovi Oliva and Zanandrea, 1959 and sea lamprey Petromyzon marinus Linnaeus, 1758.

A Novel Method for Predicting Anisakid Nematode Infection of Atlantic Cod Using Rough Set Theory

Atlantic cod ( Gadus morhua L.) is one of the most important fish species in the fisheries industries of many countries; however, these fish are often infected with parasites. The detection of pathogenic larval nematodes is usually performed in fish processing facilities by visual examination using candling or by digesting muscles in artificial digestive juices, but these methods are both time and labor intensive. This article presents an innovative approach to the analysis of cod parasites from both the Atlantic and Baltic Sea areas through the application of rough set theory, one of the methods of artificial intelligence, for the prediction of food safety in a food production chain. The parasitological examinations were performed focusing on nematode larvae pathogenic to humans, e.g., Anisakis simplex, Contracaecum osculatum, and Pseudoterranova decipiens. The analysis allowed identification of protocols with which it is possible to make preliminary estimates of the quantity and quality of parasites found in cod catches before detailed analyses are performed. The results indicate that the method used can be an effective analytical tool for these types of data. To achieve this goal, a database is needed that contains the patterns intensity of parasite infections and the conditions of commercial fish species in different localities in their distributions.

Case study of the diet and parasite fauna of and extremely rare fish species Lumpenus lampraeteformis (Perciformes, Stichaeidae) from the Gulf of Gdañsk (south Baltic Proper)

Abstract The snakeblenny, Lumpenus lampretaeformis, is a post glacial relict from the last ice age in the Baltic Sea. Reliable data on its diet, parasite fauna, distribution, population size, and population trends in the Baltic Sea are lacking. In the Polish zone it has been observed only in ICES subdivisions 25 (Slupsk Furrow) and 26 (Puck Bay, Krynica Morska, Władysławowo and Vistula mouth fishing grounds) at depths of 30-70 m; however, in recent decades only one finding of snakeblenny in Polish waters has been reported. This paper reports the record of one female specimen from the Gulf of Gdañsk. The individual’s morphological characters, stomach contents, parasitic fauna, age and gonadosomatic index were examined. The parasitological examination, which was undertaken for the first time on a specimen from the Baltic Sea since the 1930s, revealed that L. lampretaeformis was the host of one parasite species, namely a juvenile acanthocephalan Echinorhynchus gadi. Additionally, Pontoporeia fermorata and Halicryptus spinulosus were recorded in the stomach of snakeblenny for the first time in the Baltic Sea.

Studies on endangered and rare non-commercial fish species recorded in the Pomeranian Bay (southern Baltic Sea) in 2010–2013

This paper presents the results of studies on endangered and rare non-commercial fish species (Spinachia spinachia, Nerophis ophidion, Syngnathus typhle, Agonus cataphractus, Pholis gunnellus, Enchelyopus cimbrius, Cyclopterus lumpus) and one lamprey species (Lampetra fluviatilis), recorded as bycatch during monitoring surveys in 2010–2013 in the Pomeranian Bay. Two species were observed for the first time in the Pomeranian Bay: A. cataphractus and E. cimbrius. Descriptions of parasite fauna are provided for C. lumpus and E. cimbrius, which were infected with four pathogenic species from Neomonada, Digenea, Nematoda, and Acanthocephala. Almost all parasite species were new in the hosts examined.

Occurrence and distribution of parasites in relation to food components of grey gurnard, Eutrigla gurnardus (L.) (Teleostei: Scorpaeniformes), off the Shetland Islands

The research was conducted on the parasite fauna and food composition of Eutrigla gurnardus caught as by-catch in commercial catches of the Atlantic cod Gadus morhua near the Shetland Islands. Thirteen species and two genera of pathogens were identified, including six species and one genus recorded for the first time in this host. Copepoda — Euphausiacea dominated in the stomach contents (they are also the intermediate hosts for most of the parasites found), while Gadidae dominated among the fish. A checklist of E. gurnardus parasites is included.