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  • Author or Editor: Cheng Quan x
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Abstract

A new species, Syzygium guipingensis sp. nov. (Myrtaceae), is described based on mummified fossil wood from the Miocene Erzitang Formation of Guiping Basin, Guangxi, South China. This species represents the most ancient reliable fossil record of the genus Syzygium in eastern Asia, showing the greatest similarity to the extant species S. buxifolium Hook. et Arnott. Its occurrence in the Miocene is consistent with the diversification age of the Asian lineage within Syzygium as estimated by molecular dating (11.4 Ma). The fossil record of Syzygium suggests that this genus migrated from Australia to eastern Asia in the Miocene, coincidently with the formation of island chains between these continents.

In: IAWA Journal

Abstract

Meat yield is an important indicator of the commercial value of crustaceans. We investigated the correlations between morphometric characteristics and meat yield in Macrobrachium rosenbergii (De Man, 1879), in order to determine which traits were correlated with high meat yield. The association between morphometric characteristics and meat yield were estimated using statistical methods, including correlation coefficients, determination coefficients, path coefficients, and regression equations. In the same “family” [= cultured lineage or strain], the meat yield of males was often slightly lower than that of females. The meat yield of different male morphotypes ranged from 19.90% to 38.12%, while that of different female stages ranged from 30.14% to 35.59%. Among male morphotypes, the “small male” had the largest meat yield, and “old blue claw” had the lowest meat yield (P<0.05). Among the various female developmental stages, stage I had the largest meat yield, and stage III female had the lowest meat yield (P<0.05). The multivariate linear regression equation for meat yield of males contained four independent variables, and the determination coefficient was 0.744. The regression equation for females contained five independent variables, and the determination coefficient was 0.456. The characteristics that had the largest direct positive effect for meat yield were abdominal weight/body weight in males (0.862) and body length in females (0.441). These results can provide reference data for selecting M. rosenbergii with high meat yield, in order to improve the economic benefit of the prawn processing industry.

In: Crustaceana