Human chorionic gonadotrophin: a substitute for pituitary gland for induced breeding

Pituitary extract is in use for fish breeding since a long. Due to the difficulties in procuring pituitary glands and its preservation, scientists were looking for its substitute. Results on the use of human chorionic gonadotrophin in combination with pituitary for breeding of Cirrhina mrigala and Labeo rohita were encouraging. It has been possible to breed C. mrigala and L. rohita by use of HCG also. An increase in hatching percentage was observed with HCG & PG mixture in modern carp hatchery CIFE D-81.

Breeding of Indian major carps and common carp in semi-arid zone of Haryana under controlled environment

Vast barren lands are lying vacant in the semi-arid zone of India, which can effectively be utilised for fish farming. Experiments conducted in semi-arid conditions at Damdama indicated that it is possible to breed Indian major carps and common carp under controlled conditions of modern carps hatchery CIFE D-80 without depending on rain.

Distribution of Macrobrachium rosenbergii (de Man) in three rivers of Paikgacha, Bangladesh

Distribution of post larvae, juveniles and adults of Macrobrachium rosenbergii was studied in three rivers of Paikgachha, Khulna during November '91 to Apri1 '94. The adults were found to ascend upstream and the matured ones again return to the estuary to breed. Post larvae of M. rosenbergii prefer a salinity range in between 0.5 to 19.0 ppt and juveniles require a salinity range in between 0.0 to 2.0 ppt.

Studies on fecundity, sex ratio and crossbreeding in different strains of Guppy

Studies on the fecundity, sex ratio and crossbreeding in different strains of the guppy Poecilia reticulata such as Butterfly I, Butterfly II and Cobra strains was carried out. The highest fecundity among Butterfly I strain was at the 5th breed while it was highest at the 6th and 8th breed among Butterfly II and Cobra strain respectively. The average male percentage was 39.88%, 43.39% and 45.02% among Butterfly I, Butterfly II and Cobra strains respectively. The crossbreeding of strains showed good results among crossbreeds of Butterfly II (♀) X Cobra (♂) and Butterfly I (♀) X Cobra (♂). The crossbreed among the Butterfly I (♀) X Cobra (♂) proved to be excellent from the point of view of more percentage, rapid growth, and brilliant body and finnage colouration.

Breeding performance of Macrobrachium rosenbergii in captivity

The key factor in success of a Macrobrachium hatchery is to yield maximum number of larvae with minimum number of brooders. Suitable environmental conditions were provided and the breeding performance of females of M. rosenbergii was observed. A total number of 140 females brought from wild were used for this purpose. Each female was tagged and given a code number which made it possible to record the gestation period, interbreed period, number of breeding and larval yield of individual female during each breeding. Females were found to breed six times during the ten months duration. Of the total females studied, 99.12 % bred once, while only 2.16 % females bred six times in a total span of ten months. The average number of larvae decreased successively from first to fourth breeding. The average interbrood period was minimum between the first and second breeding and maximum between the fourth and fifth breeding. The highest average larval yield of 25,428 was recorded in the first breeding, the lowest of 4,596 in the fourth breeding. The possible reasons for variations in interbrood period and larval yield are discussed.

Reproductive biology, artificial propagation and larval rearing of two freshwater eels, Monopterus cuchia and Mastacembelus armatus

Studies on reproductive biology and artificial propagation including larval rearing of freshwater mud eel, Monopterus cuchia and spiny eel, Mastacembelus armatus were attempted. The gonadosomatic index (GSI) of mud eel ranged from 0.41 (August) to 5.52 (June) in males and 0.53 (August) to 7.61 (June) in females. In both cases the GSI showed a peak in June. Fecundity ranged from 228 (TL - 396 mm; W - 78g) to 5510 (TL - 865 mm; W - 630 g). In case of spiny eel, the GSI varied from 0.65 (August) to 8.30 (July) in males and 0.70 (August) to 10.46 (July) in females. GSI showed single peak in July. Fecundity ranged from 570 (TL - 240 mm; W - 30 g) to 10870 (TL - 601; W - 350g). Histology of the testes and ovaries of the eels were carried out to investigate the gonadal development stages during the reproductive months (August to November 2003). In case of male M. cuchia, the secondary primordial germ cells, primary spermatogonium, some spermatogonia A and clone of spermatogonium B in testis were observed in September. In October-males different sized lobules having spermatogonia, spermatocytes and spermatids were observed. In the ovary of M. cuchia, polygonal shaped oocytes were seen during September. The oogonia were reduced with dense and irregular shaped during October. Numerous pycnotic cells were visible during November. In male M. armatus numerous broken lobule walls were found in testes during September. In October, abundant primary germ cells, pycnotic nests of degenerating cells, spermatogonia and spermatids were observed. In females, ovaries had distinct yolk vesicles stage and yolk granules stages in August. In September, the follicular cells of the oogonia were ruptured, shrunk forming irregular shaped in October. Oogonia were also shrunk with thin, irregular shaped structure but broken parts of the ruptured follicular cells were scattered in case of M. armatus. Experimental attempts on artificial propagation indicated that both freshwater eels were difficult to breed using inducing agents like pituitary glands (PG) of 10, 20, 50, 100 and 150 mg per kg of body weight. Same doses were used for both sexes with equal sex-ratio. In both cases, brood fish died at higher doses of injection given at 100 and 150 mg PG/kg bodyweight. However, M. cuchia breed naturally in cisterns when provided with water hyacinths and tunnel in muddy bottom. M. cuchia fed with chopped cooked fish attained a mean weight of 18.75 ± 2.3 g and cent percent survival. While in case of M. armatus best growth by weight (12.0 ± 2.48 g) and cent percent survival were achieved using chopped raw fish. Car tyre was observed as best shelter for attaining the mean weight gain 22.53 ± 2.24 g and cent percent survival of M. cuchia. While PVC pipe was found to be the best shelter for M. armatus, where it attained the mean weight of 12.73 ± 1.88 g and cent percent survival.

Maturity, spawning and fecundity of Saurida tumbil (Bloch, 1795) from Mumbai waters

The absolute fecundity of Saurida tumbil ranged between 24160 to 172000 eggs with weight range of 230-670 g. Linear relationship between fecundity and weight was more valid than that of length and ovary weight. The fish breed once a year during November to March. The length at which 50% of the females mature was calculated as 296 mm. The female dominated the commercial catch and overall male to female ratio of population was 1:1.62 throughout the year.

Mitochondrial DNA variation in cattle of South China: origin and introgression

Ten restriction endonucleases were used to investigate the mitochondrial DNA restriction fragment length polymorphism (mtDNA RFLP) of 11 native cattle breeds and one cultivated cattle breed in South China. Twenty-three restriction morphs were detected, which can be sorted into five haplotypes, A phylogenetic tree of the haplotypes was constructed by using the 'upgma' method. Our study showed that haplotype I and II are identical to the zebu (Bos indicus) and taurine (Bos taurus) haplotypes, respectively. Zebu and taurine were the two major origins of cattle populations in South China, and the zebu probably had more influence on the native cattle population than taurine did. Haplotype III is identical to haplotype I of yak (Bos grunniens), which was only detected in the Diqing cattle breed. Haplotype IV was detected for the first time. This haplotype, found only in Dehong cattle, might be from an independent domestication event, probably from another Bos indicus population. Divergence of haplotypes I and IV occurred about 268,000-535 000 years ago, much earlier than the 10,000-year history of cattle husbandry. Our results also suggest a secondary introgression of mtDNA from yak to Diqing cattle.

Genome-wide SNP and haplotype analyses reveal a rich history underlying dog domestication

Advances in genome technology have facilitated a new understanding of the historical and genetic processes crucial to rapid phenotypic evolution under domestication(1,2). To understand the process of dog diversification better, we conducted an extensive genome-wide survey of more than 48,000 single nucleotide polymorphisms in dogs and their wild progenitor, the grey wolf. Here we show that dog breeds share a higher proportion of multi-locus haplotypes unique to grey wolves from the Middle East, indicating that they are a dominant source of genetic diversity for dogs rather than wolves from east Asia, as suggested by mitochondrial DNA sequence data(3). Furthermore, we find a surprising correspondence between genetic and phenotypic/functional breed groupings but there are exceptions that suggest phenotypic diversification depended in part on the repeated crossing of individuals with novel phenotypes. Our results show that Middle Eastern wolves were a critical source of genome diversity, although interbreeding with local wolf populations clearly occurred elsewhere in the early history of specific lineages. More recently, the evolution of modern dog breeds seems to have been an iterative process that drew on a limited genetic toolkit to create remarkable phenotypic diversity.

Preliminary success on hormone induced captive breeding of goldspot mullet, Liza parsia (Ham.)

An attempt was made to breed goldspot mullet, Liza parsia in captivity through hormone induction. The fish started spawning 35-36 hours after a single dose of 2ml ova prim per kg body weight. Hatching of fertilized eggs completed within 42-48 hours after spawning. The mean hatching rate (%) was 71.33±12 corresponding to the fertilization rate (%) of 64±12. The larvae started its first external feeding on the third day and attained a length 2.5±0.25 mm. The salinity of both breeding and rearing cisterns was 20‰ and temperature was maintained at 22-23°C.

Dissecting the matrilineal components of Tongjiang cattle from Southwest China

Tongjiang cattle are a local cattle population of Sichuan Province, China, numbering approximately half a million in 2005. They have long been grouped into the Bashan breed, although they have a unique breeding history and phenotypic characteristics, as w

Effects of dietary vitamin E on the growth and breeding performance of Ompok pabda

A 90 day feeding trail was conducted to investigate the effect of vitamin E on the growth and breeding performance of Ompok pabda. A total of 84 healthy female brood fish (41.10±0.44g) were divided into 4 treatments i.e. treatment T1 T2, T3 and T4 having three replications each. The fish were fed twice a day with a standard feed (40% protein) having 4 doses of vitamin E viz. 0 (served as control), 50, 100 and 150mg vitamin E/kg feed. At the end of the feeding trial, the brood fish were induced to breed with PG extract to observe the effect of vitamin Eon feed. After rearing for 90 days with the experimental feeds, it was found that weight gain and specific growth rate of brood fish fed with 100mg vitamin E/kg feed (treatment T3) was the highest (14.78±0.38g and 2.99±0.11) while 150mg vitamin E/kg feed (treatment T4) fed fish gave the poorest result (2.97±0.89g and 1.21±0.32). There was no significant difference in terms of length gain of brood fish among the different treatments. The brood fish were induced to breed with equal dose of PG extract (18 and 12mg PG/kg body weight for female and male respectively) to observe the dietary effect of vitamin E on breeding performance. The highest ovulation, fertilization and hatching rate of eggs were found to be 81.48±6.41%, 84.04±3.53% and 68.59±5.03% respectively in the brood fish of treatment T1 while the poorest (33.33±00%, 52.35±5.02% and 45.70±7.24% respectively) were found in the brood fish under treatment T4. The results suggest that inclusion of 100mg vitamin E/kg feed is best for enhancing the breeding performance of O. pabda brood fish indicating that vitamin E content has a positive impact on reproduction of fish. The present results also imply that inclusion of higher level of vitamin E exerts an antagonistic effect in terms of growth and breeding performance of this species.

Vitrification of Yunnan Yellow Cattle oocytes: work in progress

The objective of this study was to provide a simple cryopreservation method for oocytes from Yunnan Yellow Cattle and facilitate preservation efforts in this native Chinese breed, which is threatened by agricultural modernization. Cumulus-oocyte complexes (COCs) were collected from slaughterhouse ovaries and matured in vitro for 22-24 h, then selected for cryopreservation. Vitrification in open pulled straws (OPS) or in microdrops on a cooled metal surface (solid surface vitrification, SSV) was compared. The OPS vitrification solution consisted of 20% ethylene glycol (EG) and 20% DMSO. The SSV solution was a mixture of 35% EG, 5% polyvinyl-pyrrolidon (PVP) and 0.4 M trehalose. Vitrified and warmed oocytes were either fertilized in vitro or parthenogenetically activated. The rates of cleavage and development to blastocysts of fertilized oocytes following OPS versus SSV were not statistically different (38.3 and 12.5% versus 35.8 and 6.0%, respectively). The corresponding rates of parthenogenetic development to blastocysts were also not different (8.2 versus 3.5%, respectively). Development to blastocysts of non-vitrified controls following fertilization was significantly higher than that of the vitrified oocytes (22.6%, P < 0.05). These results demonstrate for the first time, that although both OPS and SSV procedures reduced embryonic development, Yunnan Yellow Cattle oocytes are capable of developing to blastocysts following cryopreservation. (C) 2002 Elsevier Science Inc. All rights reserved.

Genetic relationship of Chinese and Japanese gamecocks revealed by mtDNA sequence variation

Cockfighting has a very long history dating back to as early as 2500 years ago in China. Cockfighting was intertwined with human cultural traditions, helped disperse chickens across the world, and influenced the subsequent breed selection. Therefore, trac

Matrilineal Components and Genetic Relationship of Silkies from China and Japan

Silkie is a famous black-bone chicken breed with beautiful silky feather. The unique medical property of this chicken was recorded in Chinese traditional medicine dictionary about 700 years ago. In this study, we analyzed the mtDNA D-loop sequence variation of 26 Bairong Silkies from Fujian Province, China, together with 100 reported Silkie mtDNAs from China and Japan, and studied their matrilineal components and genetic relationship. A total of 21 haplotypes were detected, which could be assigned to six haplogroups (A-E, G). Among them, haplogroups D and G were exclusively presented in Japanese Silkies and Chinese Silkies, respectively. Chinese Silkies had higher frequency of lineages belonging to haplogroups A, B, and E, and lower frequency of haplogroup C than Japanese Silkies. For the four Chinese Silkie populations, most of samples of Taihe, Chengdu, and Hubei Silkies were grouped in haplogroups A, B, and C, whereas most of Bairong Silkies were grouped in haplogroup E. Five haplotypes were shared by Japanese and Chinese Silkies. The genetic diversity of each Silkie population varied, but the overall diversity of Chinese Silkies was similar to that of Japanese Silkies. Taken together, our results confirmed the genetic connection between Chinese and Japanese Silkies, but also clearly showed that the matrilineal genetic structures of Chinese and Japanese Silkies had some differences.