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Is the body condition of the three-spined stickleback (Gasterosteus aculeatus) determined by the type of food consumed?

Pawelec A. J., Sapota M. R., Skóra M. E.

Oceanological and Hydrobiological Studies

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2016

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Vol. 45, No. 4

588--599

EN

The three spine stickleback Gasterosteus aculeatus is a small omnivorous, wildly distributed fish. In this study, food uptake and body condition of three spine stickleback, from the Gulf of Gdansk eulitoral was investigated. Samples were taken from three locations of the Gulf of Gdańsk: in vicinities of Sopot, Chałupy and Hel. Copepods were the most quantitive food components in the three spine stickleback stomachs. In spring, at Hel station -Harpacticoida and in Sopot, crustacean and fish eggs, were dominating as a fish prey. During summer, Calanoida were most abundant in stomachs collected from fish caught in Chałupy, fish eggs and Calanoida in those from Hel station. In stomachs of fish from Sopot location most common prey were Cladocera. Comparison of stomach content to food base and Fulton’s body condition index revealed that the three spine stickleback uses available food base in efficient way.

2

Modification in the nest guarding strategy - one of the reasons of the round goby (Neogobius melanostomus) invasion success in the Gulf of Gdańsk?

Sapota M.R., Balazy P., Mirny Z.

Oceanological and Hydrobiological Studies

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2014

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Vol. 43, No. 1

21--28

EN

The round goby was noted for the first time in the Gulf of Gdańsk in 1990. After a few years, the round goby had invaded all suitable areas in the west part of the Gulf of Gdańsk. Generally, the sandy bottom was the factor that do not prevent the fish invasion. The effectiveness of reproduction is one of the most important factors in deciding the success of an introduction into a new area. The round goby needs a hard bottom for egg laying and subsequent embryo development in nests guarded by males. We observed the round goby nests in the Gulf of Gdańsk during three subsequent years. Distances between nests, nest size, number of eggs per nest, and depth of nest locations were investigated by underwater survey, from May till September, throughout the round goby spawning season. Our investigation led us to confirm that any solid elements on the bottom may be utilized as nest substrate when nesting areas are limited. Distances between nests decrease noticeably in comparison with native round goby areas. Taking into account these findings, we conclude that shallow water areas, of almost any type of bottom, might be invaded by the round goby.

3

Diet of the twaite shad Alosa fallax (Lacépčde, 1803) (Clupeidae) in the Gulf of Gdansk, the Baltic Sea

Skóra M. E., Sapota M.R., Skóra K.E., Pawelec A.

Oceanological and Hydrobiological Studies

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2012

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Vol. 41, No. 3

24-32

EN

Twaite shad Alosa fallax (12 – 48 cm total length) from the Gulf of Gdansk feed on Mysids: Mysis mixta, Neomysis integer, and fish: Sprattus sprattus, Osmerus eperlanus, and Pomatoschistus sp.. In the stomachs of A. fallax there also occur Hydrobia sp., Diptera and small stones, particles of wood and plastic. The food of inshore twaite shad measured from 12 to 21 cm centered on M. mixta. Fish are the main prey for A. fallax from the class length 22 – 31 cm from the Vistula River mouth and for all shads longer than 32 cm.

4

Trophic interactions between preadult and adult Pomatoschistus minutus and Pomatoschistus microps and young Platichthys flesus occurring in inshore waters of the Gulf of Gdańsk (Southern Baltic)

Złoch I., Sapota M.R.

Oceanological and Hydrobiological Studies

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2010

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Vol. 39, No.2

37-53

EN

We intended to estimate if shallow inshore waters of the Gulf of Gdańsk can be considered important feeding grounds for the fishes under investigation. We also examined whether competition for food exists between the investigated fishes which co-exist. The study was carried out at Sopot and Chałupy stations from summer 2001 to autumn 2003. The results showed the high importance of Neomysis integer, which exclusively lives in coastal waters, in the diet of all three investigated fish species. It indicates that they utilize this zone as a feeding ground. The obtained dataset also led to the conclusion that fish trophic niches overlap by about 40%.

5

Presence of the broad-nosed pipefish (Syngnathus typhle) in coastal waters of the Gulf of Gdańsk

Tarnowska K., Sapota M.R.

Oceanological and Hydrobiological Studies

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2007

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Vol. 36, No.2

39-48

EN

The broad-nosed pipefish (Syngnathus typhle) is a species considered threatened with extinction on the Polish Baltic coast. The presence of S. typhle in the Gulf of Gdańsk was investigated primarily by means of scuba diving, and the species was recorded at 12 of 20 sites, which were investigated. A total of 85 individuals were found. The highest numbers were observed near the mouth of the river Płutnica and near the pier in Sopot. Pipefish were found in bottom areas covered with green algae (Cladophora sp. and Enteromorpha sp.) and brown algae (Pilayella sp.), but not by vascular plants as was previously reported.

6

The fecundity and gonad development cycle of the round goby (Neogobius melanostomus Pallas 1811) from the Gulf of Gdańsk

Tomczak M.T., Sapota M.R.

Oceanological and Hydrobiological Studies

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2006

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Vol. 35, No.4

353-367

EN

The round goby (Neogobius melanostomus Pallas 1811) is a non-native species in the Gulf of Gdańsk. The aim of this article is to assess the absolute fecundity and attempt to describe the gonad development cycle of round goby specimens from the Gulf of Gdańsk. The stages of gonad development were classified according to the modified Nikolski (1963) scale for perciformes, which was adapted for the round goby. The sex ratio (female to male) in the population was 3:5. Spawning was most intense during April and July, and there was a pause in June. Fish body size determined fecundity.

7

Does food quality affect the conditions of the sand and common gobies from the Gulf of Gdańsk, Poland?

Waligóra-Borek K., Złoch I., Sapota M. R., Fijałkowska M., Forycka K.

Oceanological and Hydrobiological Studies

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2005

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Vol. 34, No.3

39--55

EN

Sand and common goby specimens were collected from the costal waters in the vicinity of Sopot and Chałupy (Gulf of Gdańsk) from August to October. The relationship between the food consumed and the fish condition was investigated for both species using the Fulton and Clark factors, HSI, feeding intensity, and the index of relative importance. The results indicated that the mean values of the common goby condition factors (20 – 29 mm) were higher in September, the last month of reproduction. The sand gobies (30 – 39 mm) were characterized by lower condition factor values in September, one month after spawning. It was concluded that there is a direct link between diet composition and goby condition during spawning and in the months following it.

8

Waligóra-Borek K., Sapota M. R., Forycka K.

Oceanological and Hydrobiological Studies

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2005

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Vol. 34, No.3

57--68

EN

In the Polish costal zone of the Baltic Sea two similar looking gobies – sand goby and common goby occur. In quantitative investigation both species are often taken as an one, because of difficulties in distinguish them. There are a few methods to differentiate sand goby and common goby - body pigmentation, shape of head and pigmentation of a spleen (Ławacz 1965). During the investigation it was proofed that compared species differ from each other also in biological characteristic. In the Gulf of Gdańsk spawning-season starts for sand goby in March and ends in September, for common goby it lasts from March to August. They have different sex ratio, but they have similar range of a HSI and GSI coefficients. Those differences and similarities are important for future investigations because they show that sand goby and common goby should be separated in studies

9

Breeding characteristics of the sand goby (Pomatoschistus minutus) - one of the most abundant goby species in the costal waters of the Gulf of Gdańsk region (southern Baltic Sea)

Waligóra-Borek K., Sapota M. R.

Oceanological and Hydrobiological Studies

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2005

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Vol. 34, No.4

47--55

EN

The reproduction aspect of the biology of Pomatoschistus minutus was investigated on fish collected in the Gulf of Gdańsk from March to October 2002. The study zone was from the shore to a depth of about 1 m. The sand goby is common in the investigated area from July to October, but it migrates to deeper water in the colder months. The highest numbers of individuals were observed in September. The spawning season of the sand goby in the Gulf of Gdańsk is from April to August. It is so long because this species is batch spawner. The study confirmed a dependence between the HSI and GSI indexes as well as the dependence between relative fecundity and fish length.

10

Species composition and size structure of beach seine by-catches in Port-Said fishing harbour, Egypt

El-Mor M., El-Etreby S., Sapota M.R.

Oceanological Studies

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2002

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Vol. 31, No. 3-4

31-43

EN

The trash catch of the Egyptian Mediterranean small beach seine operating in Port-Said fishing harbour at the entrance of the Suez Canal during the period from January to December 1997 was analyzed. It amounted about 3-5 kg per haul composed of three categories: juveniles of commercially important species (76.6%), low-valued small size fish species (11.2%) and 12.2% of non-edible "trash" species. The amount of trash catch constituted about 20-25% of the total landing of beach seine. It was classified into 42 species representing 24 families. Among these, 17 species are known to be of Red Sea origin. Three species Siganus rivulatus, (recruitment in October), Terapon puta (recruitment in August and September) and Pomadasys incisus (recruitment in January and February) dominated the assemblage of 42 species and contributed 53.8% of all sampled fishes.

11

Biological studies on juvenile fish of Siganus rivulatus (Forsskal 1775) in Port-Said fishing harbour, Egypt

El-Mor M., El-Etreby S., Sapota M.R.

Oceanological Studies

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2002

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Vol. 31, No. 3-4

17-30

EN

A total of 999 specimens of Siganus rivulatus were collected from trash catches of small beach seine operating in the Port Said fishing harbour at the entrance of the Suez Canal during the period from January to December 1997. The species constituted 20.1% of the trash catch and about 4 - 5% of the total catch of the gear. The juveniles of S. rivulatus could stay at the nursery grounds from October till April, and be recruited from October till December. The length-weight relationships, as well as the condition factor of the juvenile fish, were studied. The feeding activities were quite high in winter months. From May to September, juveniles of S. rivulatus appear to be exclusively deposit feeders in most months, feeding mainly on algae and molluscs.

12

A study on trash catch of the bottom trawl along Port-Said coast, Egypt

El-Mor M., El-Etreby S., Mohammad S., Sapota M.R.

Oceanological Studies

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2002

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Vol. 31, No. 3-4

45-55

EN

The trash catch of an Egyptian Mediterranean trawling net was analyzed. The catch amounted to approximately 15-20 kg per haul, composed of three categories: Juveniles of commercially important species (86.5%), Low-value small size fish species (5.5%) and non-edible species (7.9% of the total trash catch). In the catch, 35 species were identified representing 22 families. Among these, 11 species are known to be of Red Sea origin. The amount of trash catch constituted about 15-20% of the total landing of trawling net. Three species, Diplodus annularis (recruit in July and August), Dicentrarchus punctatus (recruit in June and July) and Sardinella aurita (recruit in September and October) were the most abundant fish species representing 20.5%, 18.9% and 17.9% of the total trash respectively.

13

Spatial (depth dependent) and temporal distribution of fish in sandy eulittoral of the tip of the Hel Peninsula (the Gulf of Gdańsk - Baltic)

Sapota M.R.

Oceanological Studies

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2001

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Vol. 30, No. 3-4

77-89

EN

Presence of fish from 10 species was confirmed in shallow close to shore waters on the tip of the Hel Peninsula, in period from early spring to late autumn. Zone from shore to 5 meter depth was investigated. The highest number and biomass were noticed in summer on 3 meter depth. As general biodiversity taking into account number increases with increasing depth, whereas biodiversity taking into account biomass is not so depth dependent. Flounder is the absolute dominant at all depths in investigated region. Common goby and three spined stickleback are two other significant species. Comparison of data from all investigated depths shows that sampling in the most close to shore zone (1 meter depth) let well describe fish community of near shore shallow waters in investigated area.

14

Recrutation and settlement of young flounder (Platichthys flesus) in the western part of the Gulf of Gdańsk (Baltic)

Sapota M.R., Kamińska U.

Oceanological Studies

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1998

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Vol. 27, No. 3

31-42

EN

On a basis of whole year monthly sampling, the abundance of the flounder in inshore shallow waters of the western part of the Gulf of Gdansk was established. Flounders were observed almost all year. Only in winter, when sea ice forming proc-esses occurred, they disappeared from the investigated zone. The highest abundance of the flounder was noticed in Hel vicinity. No flounders were observed in inshore waters of the Puck Lagoon. Young flounders occurred in the highest number in July (average for all investigated area amounted to 2.81 individuals 100/ m^2). In that month, this-year-born flounders settle in the inshore shallow water zone. The highest biomass was noticed in August (average 4.98 g/100 m^2) when older bigger flounders more frequently inhabited inshore zone. Body proportions of young flounders during their growth in inshore shallow waters of the Gulf of Gdansk are stable. All measured distances were increasing linearly with the growth of flounder length.

15

Growth of the young flounder (Platichthys flesus) in inshore shallow waters of the Gulf of Gdańsk

Sapota M.R., Mudrak S.

Oceanological Studies

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1998

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Vol. 27, No. 3

19-29

EN

The age and rate of growth of the flounder from inshore shallow waters of the Gulf of Gdansk (from shore to 1-m depth) have been investigated. Mainly the flounder from 0 and 1-year age group exists in this zone. Flounders from 0-year age group enter shallow waters of the Gulf of Gdansk in June or July. They stay in this area till the end of the year. Flounders from 1-year age group are represented in the investigated zone all year. Bigger individuals from this group migrate into deeper waters.