Comparison of seasonal activity of the lake minnow, Eupallasella percnurus (Pall.), and crucian carp, Carassius carassius (L.), in small water bodies in northern Poland
This paper presents preliminary results of a comparison of the seasonal activity of lake minnows, Eupallasella percnurus (Pall.), and crucian carp, Carassius carassius (L.), in a few small water bodies. Field studies were conducted based on catches made with baited traps in periods without ice cover from April to December 2006. E. percnurus became active earlier than did C. carassius and their period of intense activity was longer. The first E. percnurus appeared in the traps in early April when the ice was still melting, and these fish were caught at a temperature range of 3.5-29.2°C. C. carassius were caught most abundantly in the beginning of May at temperatures from 15°C; this species was usually noted in traps at a narrower, but higher, temperature range in comparison with the E. percnurus. Additionally, the activity of both these species was similar with regard to weather conditions; both species were less active on cloudy days and when atmospheric pressure was increasing.
Phototaxis in climbing perch (Anabas testudineus) was investigated by subjecting fish to LED light traps (blue, green, yellow, orange, red, white) and control (total 13 traps). The trap was constructed of polyamide (PA) nylon monofilament (31.75 mm mesh size), fastened around two wire ring frames (∅ 490 mm) with a net height of 270 mm. A lamp was placed on the bottom of the trap. 96 individuals, consisting of 34 males and 62 females, were analysed. Both continuous and blinking light traps were considerably higher in the number of catch compared to the control. The body size of catch ranged from 76-135 mm TL and 8.00-55.00 g W. The mean YPUEs (yield per unit effort) for male and female were 4.00 ± 2.25 and 7.00 ± 4.50 g trap−1 trial-1, respectively. The CPUEs (catch per unit effort) for continuous, blinking light traps and the control ranged from 0.43 to 0.93, 0.21 to 0.86, and 0.21 fish trap−1night−1, respectively. The mean condition factor (K) values of 2.10 ± 0.40 for males and 2.13 ± 0.34 for females indicate fish with better condition. Positive group responses of fish were more pronounced in the middle size classes between 90 and 109 mm TL. Negative allometric growth pattern (b) (1.7271-1.8828) was observed, indicating that the culture system should be refined. A. testudineus showed positive phototaxis to the “colors of light”. In addition, efforts to collect climbing perch from the wild for breeding and commercial purposes may benefit from this study.
occupation presented by the archeological sites along Chao Phraya River. Many archeological sites with exhibitions present the ancient communities with local boats, old fishtraps, and agriculture equipment along this river. It also has many activities and attractions to offer to tourists, such as cruises, floating restaurants, local market, viewpoint tower, and Chinese shrines. Local raw materials have been developed as souvenir items of the area, consisting of clay (pottery), rice (crisp rice) and fish (fish balls and Thai fish cakes). Fig. 4 Geologic features in Nakhon