Reproductive biology of the Rote Snake-necked Turtle Chelodina mccordi (Rhodin, 1994) in Oelsonbai Captivity, Kupang

The Rote snake-necked turtle (Chelodina mccordi Rhodin, 1994) or Kura-kura Leher Ular Rote is an endangered species endemic to Rote Island, East Nusa Tenggara. It is listed as Critically Endangered by the IUCN. However, based on surveys in recent years, C. mccordi was presumed extinct in the wild. Ex-situ conservation is one alternative to conserve C. mccordi. The purpose of this paper is to describe the reproductive biology of the Rote snake-necked turtle in captivity. Three (one male and two female) C. mccordi were observed in Oelsonbai captivity, Kupang, from 2009 to 2020 to obtain data on the species’ reproductive biology. The first mating behaviour was observed when the turtles were six years old. Hatches occurred two or three times a year, with clutch size varied from five to twenty eggs. Egg hatchability was 75-100 percent, with an incubation period of 76 to 102 days. Female size when mature straight-line carapace length (SCL) 178 mm, carapace width 145 mm, and plastron length 142 mm. Male size straight-line carapace length (SCL) 190 mm, carapace width 150 mm, and plastron length 143 mm.

Yakemys multiporcata n. g. n. sp., a Large Macrobaenid Turtle from the Basal Cretaceous of Thailand, with a Review of the Turtle Fauna from the Phu Kradung Formation and Its Stratigraphical Implications

Yakemys multiporcata n. g. n. sp. is described on the basis of shell elements from the upper part of the Phu Kradung Formation (basal Cretaceous), Khorat Plateau, NE Thailand and assigned to Macrobaenidae. The new taxon is unusually large for an early macrobaenid (with an estimated carapace length about 70 cm) and is characterized by a large, rounded, low shell, the presence of a midline keel and numerous additional strong ridges on the carapace, the anterolateral margin upturned to form a gutter, posterolateral peripherals mesiolaterally expanded, narrow vertebrals, the vertebral 4 triangular and narrowed posteriorly, a greatly reduced plastron with a short bridge, an oval and elongate entoplastron with reduced ventral exposure, and strip-shaped epiplastra. The discovery of a macrobaenid turtle provides further support for an Early Cretaceous age for the upper part of the Phu Kradung Formation.

Analysis of Crayfish Catches Using Bubu Wau in Laut Tawar Lake, Central Aceh, Aceh

Laut Tawar Lake is located in the town of Takengon, Central Aceh district. Currently, Laut Tawar Lake has been utilized by the surrounding community as a fishing spot. One of the fishing gears used by fishermen is Bubu wau. One of the catches obtained by fishermen is crayfish. The crayfish has a high economic value, so the lack of control over the intensity of the catch also causes the average size of the crayfish caught, because catching crayfish is a transition from catching Rasbora tawarensis. One of the problems that frequently occur and research on crayfish has never been done before. Therefore, this research needs to be done. The purpose of this study was to determine fishing catch compositions of Bubu wau and the size distribution of crayfish carapace length of Bubu Wau fishermen in the Teluk One-one, Laut Tawar Lake. The research was carried out in about March 2021. The description of the fishing catch composition was analyzed by using the describded method. The size distribution of crayfish carapace length was analyzed by the Sturgess rule. From the results of the study, it can be concluded that the catch compositions of Bubu wau in Teluk One-one are crayfish, suckermouth catfish, channeled apple snail and tilapia. The type of crayfish caught by fishermen’s Bubu wau was Cherax quadricarinatus amount of 4232 individuals (89% of the total catch), where the total length of the dominant crayfish carapace was 4.4-4.9 cm with a total number of 1403 and the least with a size of 8.6-9.1 cm was 1 crayfish from the total catch

A Study on Some Biological Parameters of Crayfish (Astacus leptodactylus Eschscholtz, 1823) in Ulugöl, Samsun, Turkey

The study aimed to investigate some morphometric traits, length-weight relationship, meat yield, fecundity and some biochemical compositions of Astacus leptodactylus, in one of the Bafra Fish Lakes named Ulugöl, Samsun, Turkey. A total of 378 A. leptodactylus (198 female and 180 male) were examined. The average carapace length was 50.96±0.46 mm for females, 51.31±0.66 mm for males and 51.13±0.40 mm for all sampled crayfish. Abdomen length was 52.36±0.49 mm for females, 49.26±0.62 mm for males and 50.87±0.40 mm for all sampled crayfish. Live weight was between 14.38 g and 105.03 g with an average of 38.26±0.73 g. The average weight of females was less than that of males. There was a strong relationship between length and weight. The weight of crayfish with pleopodal eggs ranged from 28.24 g, to 59.50 g with an average of 41.73±1.09g. The average number of eggs per individuals was 192.90±9.94 with an average number of 4.62±0.21 per unit of live weight. The average total egg weight was 3.35±0.19 g while the average egg diameter was 2.17±0.03 mm. Abdomen meat was lower for males comparing with females. Average moisture, crude ash, crude oil and crude protein of abdomen meat were 81.27%, 1.47%, 0.81% and 16.45%, respectively.

Carapace Length-Weight Relationship and Condition Factors of Macrobrachium rosenbergii in The Rivers of Riau Province, Indonesia

Macrobrachium rosenbergii in Riau Province are almost found in all inland waters, especially in the big rivers, namely Indragiri, Kampar, Siak and Rokan. This species are still the main catch of fishermen even the catch has decreased. Deforestation along the watershed, decreasing water quality and habitat have a very bad impact on Macrobrachium rosenbergii. This study was conducted to determine the relationship of carapace length-weight and the condition factor of Macrobrachium rosenbergii in the rivers of Riau Province. The study used a survey method from May to June 2021. Data collection was carried out in the rivers of Riau Province at the center for giant prawns. Sampling was done randomly from the catches of fishermen. The biological parameters measured were carapace length and weight. The results showed that the relationship between carapace length and weight of giant prawns in the Siak River, Rokan River and Kampar River are 0.0008L2.8473, 0.0049L2.3906 and w = 0.0014L2.643, respectively. The length of the carapace can determine the weight of prawns up to 78.62-96.62%, where the relationship between carapace length and weight is very close. The growth pattern of giant prawns is allometric and the condition factor is 1.03-1.05.

Length–weight relationship of Charybdis callianassa Herbst, 1789 (Decapoda: Brachyura) in relation to sex and carapace length along the Mumbai coastal water, India

Background The present study was performed to determine carapace length–body weight relationship of Charybdis callianassa. In fisheries biology, length–weight relationships are important as they allow for the calculation, by creating a mathematical equation between the two, of the total weight of the fish in a particular group in fish. Such information is helpful for fishery scientists to research the dynamics of development and populations and for public agencies that can maintain and preserve these resources sustainably. Results A study on the carapace length–body weight relationship of Charybdis callianassa (Herbst, 1789) was made on the northwest coast of India for the first time. The study was based on experimental trawl fishing conducted fortnightly from August 2019 to March 2020. A total of 479 specimens, including 262 males and 217 females from fishing trawler, were examined for their carapace length and total weight. The carapace length ranged from 2.69 to 3.54 cm, and the total weight from 5.26 to 7.36 g. This analysis revealed that the crabs exhibited negative allometric development, as shown by average exponents 'b' = 2.71 for pooled data with high coefficient (r) = 0.91 and r2 = 0.83. Conclusions The carapace length–body weight relationship of Charybdis callianassa in relation to sex and carapace was studied in the Mumbai coastal water, India. We found major differences in the average “r2” values of species reported for males (0.89), females (0.79) and pooled data (0.83). Such kind of study is essential for fisheries biology to comprehend the differences in circumstances in small and large specimens that vary with environmental conditions and seasons.

Glebych minutissimus gen. et sp. nov., the smallest cobweb spider (Araneae: Theridiidae)

Glebych minutissimus gen. et sp. n., (♂♀), a minute six-eyed and apparently lungless theridiid spider, inhabiting epiphytes in foggy-forest belt at Peruvian Andes is described, representing the smallest (total length varies from 0.79 to 0.92 mm, carapace length ca. 0.36 mm) member of the family. Glebych gen. n. is related to the Neotropic genus Styposis Simon, 1894, which is small-sized and six-eyed as well.

Population dynamics of pronghorn spiny lobster (Panulirus penicillatus) in Palabuhanratu Bay, Sukabumi, West Java

Pronghorn spiny lobster (Panulirus penicillatus) is one of the dominant lobsters and has high economic value. The fishing activities are conducted continuously and put aside the preservation of these resources. This study purposed to analyze the population dynamics of pronghorn spiny lobster (Panulirus penicillatus) in Pelabuhanratu Bay, Sukabumi, West Java. The data were collected from January until December 2016 with samples from local fisherman. Lobsters were measured carapace length and total weight. Data analysis included the relationship between length and weight, growth parameters, recruitment patterns, mortality, exploitation rate, length at first maturity or incubating eggs (Lr), and length for first capture (Lc). Panulirus penicillatus from the Palabuhanratu Bay has growth pattern of a negative allometric in both males and females. The asymptotic carapace length (CL∞) of males is higher than females while the growth coefficient (K) of males is lower than females. The peak recruitment for males is expected to be in April and July, while for females in May and August. The total mortality rate of males is higher than the natural mortality rate and vice versa for females. The male lobsters have occurred overexploitation, while females have not occurred overexploitation. The female lobsters have an Lr <Lc value which indicates that the female lobsters are caught after incubating the eggs.