A total of 504 observations of nest building behaviour and the re-use of sleeping nests exhibited by 10 individuals of Sulawesi babirusa (Babyrousa celebensis) were made in spacious outdoor enclosures on Bali, Indonesia. We recorded behavioural characteristics associated with the timing of nest building behaviour, nest sites, and selection of nestbuilding materials. Both sexes frequently participated in the construction of sleeping nests during the short period from 17:00 hr to 18:00 hr, which corresponded to the period between the evening feed and the time of sunset. Young babirusa contributed from the age of 15 weeks. The babirusa favoured specific nesting sites in the enclosures determined by available structural supports such as walls, trees or corners. Various kinds of plant materials available in the enclosure were used. In addition to picking up fallen plant matters, they also pulled various parts off trees while standing on the hind limbs. In one instance, parts of a wooden fence were used due to the lack of other nesting materials. When housed as a group, consistent leadership of the nesting behaviour was not recognised; they seemed to prefer cooperative behaviour and built a communal nest. We concluded that nest building behaviour, for resting and sleeping, was a normal and important behaviour of the babirusa and that the provision of nest building materials to captive babirusa was an effective form of enrichment.

Population structure, growth, length-weight relationship, mortality and stock size of tench, Tinca tinca (L.), was studied in Lake Beys¸ehir, Turkey in 2005. Totals of 3360 tench (1865 males; 1795 females) were captured with gill-and trammel-nets of various mesh sizes. Male to female ratio was 1.04 : 1. The study covered length year classes. Fork lengths and total weights ranged from 9 to 37 cm and 13 to 815 g. For all individuals, the von Bertalanffy growth equation and lengthweight relationship were L t = 54.2[1)exp()0.1350(t + 1.0281)] and W = 0.0151 L 2.9993 , respectively. Growth performance index and mean condition factor of the tench population were 2.598 and 1.513, respectively. Mortality rates were Z = 1.97 year )1 , M = 0.29 year )1 and F = 1.68 year )1 for total, natural, and fishing mortality, respectively. The exploitation rate was E = 0.85, and the percentage of surviving fish was 13.9%. Tench stock was assessed as about 6-7 million individuals and 1450-1500 tonnes in biomass. It was determined that maximum sustainable yield could be obtained with an 80% level of the current fishing effort.

This paper was carried out from 15 June to 24 December in 2000 in Lake İznik of Turkey, to determine catch per unit effort (CPUE) and size composition of crayfish, Astacus leptodactylus Eschscholtz 1823, captured by fyke-nets of local fishermen. The average CPUE of all size groups was found as 1.65 crayfish/fyke-net/night for fishing season in 2000, but 26.4% of which was below the legal minimum size (crayfish<90 mm). The average CPUE of legal-sized (crayfish≥90 mm) crayfish was 1.10 crayfish/fykenet/night. The annual catch of crayfish was estimated as 2990 tonnes. The length and weight compositions of crayfish captured in the fyke-nets have varied between 60 and 130 mm, and 6 and 71 g, respectively. The mean length and weight were found as 95.5 mm and 28.8 g for all size groups and 100.1 mm and 33.0 g for legal-sized individuals.

The feeding behaviours of the Sulawesi babirusa (Babyrousa celebensis) were investigated in an enclosure imitating the early phase of a commercial coconut palm (Cocos nucifera) grove. Unexpected behaviours, such as the eating of coconut flowers and the picking of young coconut fruits, were observed. Additionally, we conducted experiments in which we fed several different parts of the coconut palm to the animals. We found the following: 1) coconut seedlings and leaflets were not eaten; 2) the babirusas preferred to eat staminate flowers rather than carpellate flowers; 3) the babirusas were able to crush the young coconut fruits with its teeth, but failed to open the mature coconuts; 4) the maxillary and mandibular incisors gripped the coconut, and the tip of the mandibular incisor was then used to penetrate the coconut surface to crack it open; 5) the palatable parts were the kernel and haustorium of the mature coconut.The coconut parts eaten by the babirusas in the experiment were concordant with the pieces of broken kernels and haustorium scattered over coconut groves in copra production. These pieces have no economic value for the farmer.There was insufficient evidence to support the view that babirusas moving through coconut groves constitute vermin for the coconut farmers and copra producers.

Efficiencies of different trammel net types on capture of tench, Tinca tinca L. were investigated in Lake Beyşehir in Turkey between April 1998 and August 1999. Nets with an inner wall of monofilament and outer walls of multifilament (type A) were more efficient than the other net types (type B, monofilament inner and outer walls; type C, multifilament inner wall and monofilament outer walls; and D, multifilament inner and outer walls). Type A nets were 2.08, 1.79 and 1.08 times more effective than the types D, C and B for catching tench. Monofilament inner walls of trammel nets were on average 1.85 times more effective than multifilament inner walls. No significant difference in catching efficiency of monofilament and multifilament outer walls was found (P>0.05). The average size of tench caught in monofilament trammel nets was higher than those caught in multifilament trammel nets, although not significantly different.