Assessment of the Characteristics of Demersal Fish Communities Using Species-and Trait-Based Approaches in the Coastal Habitats Along Rongcheng Bay,Shandong Peninsula,China

Biodiversity declines have motivated many studies on the relationship between species diversity and ecosystem functioning.In this study,we described the spatial-temporal characteristics of demersal fish communities along a coastal habitat in Rongcheng Bay,Shandong Peninsula,China with both species-based and biological trait-based approaches.The field survey was carried out monthly using traps from April to October of 2018,and divided into three seasons(spring:April and May;summer:June,July and August;autumn:September,October and November).The study area included five distinct habitats:seagrass bed,natural rocky reef,bare sand,artificial reef together with natural rocky reef,and artificial reef together with bare sand.We analyzed the fish communities with three taxonomic diversity indices,including Shannon-Wiener,Simpson,and Pielou Evenness,as well as four functional diversity indices,including FRic,FEve,FDiv,and FDis,based on 7 functional groups which are categorized into 27 traits.The results showed that there were no significant differences in taxonomic diversity indices among different habitats in the three seasons.However,significant differences were found in the functional richness of fish communities among different habitats in three seasons.Seagrass bed represented the highest functional richness in spring and autumn.This study demonstrates that seagrass bed is very important in enhancing the functional diversity of fish communities in a complex habitat.The study also indicates that the combination of taxonomic diversity and functional diversity will provide a more detailed description of the characteristics of fish communities.

Dynamics of a stochastic Holling II predator-prey model with Levy jumps and habitat complexity

This paper investigates a stochastic Holling II predator-prey model with Levy jumps and habit complexity.It is first proved that the established model admits a unique global positive solution by employing the Lyapunov technique,and the stochastic ultimate boundedness of this positive solution is also obtained.Sufficient conditions are established for the extinction and persistence of this solution.Moreover,some numerical simulations are carried out to support the obtained results.

Habitat values for artificial oyster (Crassostrea ariakensis) reefs compared with natural shallow-water habitats in Changjiang River estuary

Oyster reefs have an equivalent, complex 3-dimensional structure to vegetated habitats and may provide similar functions in estuarine environments. Nevertheless, few studies have compared oyster reefs with adjacent natural shallow-water habitats. Here the resident benthic macroinvertebrate communities in an artificial oyster （Crassostrea ariakensis） reef and in adjacent natural estuarine shallow-water habitats （salt marsh, intertidal mudflat, and subtidal soft bottom） in the Changjiang （Yangtze） River estuary were described. The mean total densities and biomass, Margalef＇s species richness, Pielou＇s evenness and Shannon-Weaver biodiversity indices of the resident benthic macroinvertebrate communities differed significantly among the habitats. Significantly higher densities and biomass of benthic macroinvertebrates occurred in the oyster reef compared with the other three habitats. Ordination plots showed a clear separation in benthic macroinvertebrate communities among the four habitat types. The results demonstrated that the artificial oyster reef supported distinct and unique benthic communities, playing an important role in the complex estuarine habitat by supplying prey resources and contributing to biodiversity. In addition, the results suggested that the oyster reef had been restored successfully.

The evolution of complex brains and behaviors in African cichlid fishes

In this review, I explore the effects of both social organization and the physical environment, specifically habitat complexity, on the brains and behavior of highly visual African cichlid fishes, drawing on examples from primates and birds where appropriate. In closely related fishes from the monophyletic Ectodinii clade of Lake Tanganyika, both forces influence cichlid brains and behavior. Considering social influences first, visual acuity differs with respect to social organization （monogamy versus polygyny）. Both the telencephalon and amygdalar homologue, area Dm, are larger in monogamous species. Monogamous species are found to have more vasotocin-immunoreactive cells in the preoptic area of the brain. Habitat complexity also influences brain and behavior in these fishes. Total brain size, telencephalic and cerebellar size are positively correlated with habitat complexity. Visual acuity and spatial memory are enhanced in cichlids living in more complex environments. However habitat complexity and social forces affect cichlid brains differently. Taken together, our field data and plasticity data suggest that some of the species-specific neural effects of habitat complexity could be the consequence of the corresponding social correlates. Environmental forces, however, exert a broader effect on brain structures than social ones do, suggesting allometric expansion of the brain structures in concert with brain size and/or co-evolntion of these structures [Current Zoology 56 （1）： 144-156, 2010].