Topic
Licha
About: Licha is a research topic. Over the lifetime, 9 publications have been published within this topic receiving 92 citations.
Papers
TL;DR: The assumption that the Western NR6A1 haplotypes were introduced into Licha Black and possibly Laiwu and are associated with increased vertebral number is supported.
Abstract: There is evidence that NR6A1 is a strong candidate for being a causal gene underlying vertebral number in pigs. The Licha Black is one of the leanest Chinese indigenous pig breeds, having an average vertebral number of 21.5. The introgression of Western germplasm into Licha Black, resulting in increased vertebral number, has been assumed but is not confirmed. This study detected allele frequencies of the NR6A1 causative mutation (c.575T>C) in 519 pigs from three Western and seven Chinese breeds including Licha Black, and evaluated the genetic variation in a 650-kb region containing NR6A1 in the 10 breeds. Allele T for increased vertebral number was fixed in Western breeds. In contrast, this allele was very rare in most of the Chinese native breeds. Notably, the T allele was present in the Licha Black at a rather higher frequency (0.585) and in the Laiwu at lower frequency (0.250). As expected, selection pressure has wiped out the genetic variability in the 650 kb region in Western breeds. Conversely, Chinese indigenous breeds showed a high degree of genetic variability in this region. However, the Licha Black displayed dramatically reduced heterozygosity at the loci proximal to the causative mutation. Moreover, a high proportion (45.9%) of Licha Black pigs and a small number (21%) of Laiwu pigs had the Western NR6A1 haplotype, and the two breeds showed closer relationships with Western commercial breeds than other Chinese breeds in the phylogenic tree. When the results are taken together, this study supports the assumption that the Western NR6A1 haplotypes were introduced into Licha Black and possibly Laiwu and are associated with increased vertebral number.
48 citations
TL;DR: The males of Scymnorhinus licha have a higher coefficient of repletion and a higher average of prey per stomach and show a greater preference for sharks and bony fishes.
Abstract: A study has been made of the diet of Scymnorhinus licha in Catalan coastal waters by means of the analysis of the stomach contents of 97 specimens caught at depths ranging from 300 to 600 metres during a 12 month survey. The annual coefficient of repletion is 80%. Bony fishes form the basic group in the diet for all seasons: they are followed by sharks, crustaceans and cephalopods, which are secondary. As the size of G. licha increases, there is an increase in the frequency of crustaceans and sharks in the stomach contents and a drop in the frequency of cephalopods. Bony fishes are slightly more frequent in the larger specimens. The males have a higher coefficient of repletion and a higher average of prey per stomach and show a greater preference for sharks and bony fishes.
39 citations
TL;DR: The first experimental study of three luminous sharks from New Zealand provides an insight into the diversity of shark bioluminescence and highlights the need for more research to help understand these unusual deep-sea inhabitants: the glowing sharks.
Abstract: Bioluminescence has often been seen as a spectacular yet uncommon event at sea but considering the vastness of the deep sea and the occurrence of luminous organisms in this zone, it is now more and more obvious that producing light at depth must play an important role structuring the biggest ecosystem on our planet. Three species of deepwater sharks (Dalatias licha, Etmopterus lucifer, and Etmopterus granulosus) were collected from the Chatham Rise, off New Zealand, and for the first time, we documented their luminescence. Comparison of glowing shark pictures, combined with histological description of light organs and hormonal control analysis, highlight the evolutive conservation of the bioluminescence process within Dalatiidae and Etmopteridae. A special emphasis is placed on the luminescence of D. licha, the largest known luminous vertebrate. This first experimental study of three luminous shark species from New Zealand provides an insight into the diversity of shark bioluminescence and highlights the need for more research to help understand these unusual deep-sea inhabitants: the glowing sharks.
20 citations
1 Jan 2008
TL;DR: Investigations conducted off the Maghreb coast allowed to capture 47 kitefin sharks Dalatias licha (Bonnaterre, 1788) and to state that the species is not completely extincted in the area, suggesting that it probably reproduces in alternate years.
Abstract: Investigations conducted off the Maghreb coast allowed to capture 47 kitefin sharks Dalatias licha (Bonnaterre, 1788) and to state that the species is not completely extincted in the area. In the observed sample, males significantly outnumbered females (df = 1; χ2 = 4.8; p > 0.05), with sex-ratio F: M = 1: 2.1. All males over 740 mm TL were adult. A pregnant female carried 6 developing embryos, 3 males and 3 females, between 340 and 360 mm TL, which exhibited a conspicuous yolk sac. In the female, both ovaries were in a resting phase, suggesting that the vitellogenesis and embryonic development were not concomitant in D. licha. The species probably reproduces in alternate years. The breeding period occurs in the summer in the region. D. licha feeds mainly on fishes, occasionally on cephalopods.
18 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 1 |
| 2018 | 3 |
| 2011 | 1 |
| 2010 | 1 |
| 2009 | 1 |
| 2008 | 1 |