Redescription of a rarely encountered species Travisachinensis Grube, 1869 (Annelida, Travisiidae), including a description of a new species of Travisa from Amoy, China.

The original description of Travisiachinensis Grube, 1869 was incomplete, leading to confusion with other species. To clarify the status of this species, we provide a redescription of, and remarks on, T.chinensis based on an examination of the type specimen. We also describe Travisiaamoyanus sp. nov., collected from Xiamen (Amoy), China, and originally identified as T.chinensis by Monro (1934). The new species can be distinguished from its congeners by a combination of the following characters: the total number of segments (34 or 35) and chaetigers (33 or 34), parapodial lappets first from chaetiger 15, and a pygidium with a large ventral triangular cirrus and about six encircling lateral cirri. Genetic distances and phylogenetic analyses based on the mitochondrial (16S rRNA) and nuclear (18S rRNA) genes support the identity of the new species.

Comparison of benthic nematode assemblages in native mangrove forest and exotic mangrove plantations (Sonneratia apetala Buch-Ham) along the South China Coast.

The exotic mangrove species Sonneratia apetala has been planted widely in China since 1985. As an exotic mangrove species, it is important to understand the influence of Sonneratia plantations on marine nematode assemblages. We studied the Zhanjiang and Xiatanwei mangrove wetlands on the South China Coast during the four seasons of 2010 and 2019. The results showed that S. apetala plantations increased the number of genera, Shannon-Wiener diversity, richness, evenness, maturity index (MI) and decreased the index of trophic diversity (ITD) values for nematodes compared to those in mudflats, but did not change significantly compared to those of native mangrove forests. In addition, Sonneratia plantations did not significantly change nematode assemblages compared to those of native mangroves, though they did change significantly compared to those in mudflats. Thus, interplanting S. apetala into native mangrove forests may be an effective substitute for using native mangroves in mangrove plantation.

[Reflections on construction of the experimental course system for environmental science in colleges and universities].

The training effects of experimental courses determine the practical abilities of undergraduate students. Therefore, it is essential to establish a comprehensive experimental course system that adapts to the undergraduate education of environmental science. Here, we introduce the "basic-specialized-comprehensive" experimental course system of Xiamen University, which is established following the principles of being systematic, comprehensive, and modular. To establish this course system, we first increased the investment of lab facilities and enhanced the management of student labs. Then, we improved the contexts of teaching and training according to the requirements of industry and society. Showing how this course system is developed stepwise and the training effects of this system, we hope to provide a reference for the experimental courses of environmental science in colleges and universities.

How do spatial and environmental factors shape the structure of a coastal macrobenthic community and meroplanktonic larvae cohort? Evidence from Daya Bay.

We examined the relative importance of spatial processes (dispersal-related) and environmental processes (environmental selection-related) in community structure for macrobenthos (including juveniles and adults) and meroplanktonic larvae in the subtidal areas of Daya Bay, China. We found that both macrobenthos and meroplanktonic larvae showed similar spatial patterns, both following the distance-decay relationship. The results of variation partitioning analysis (VPA) showed the roles of both spatial and environmental factors in governing the assembly of both communities, although both explained only a small (slightly larger for spatial factor) fraction of the community variation. We also found that macrobenthos were more affected by spatial processes than meroplanktonic larvae. In addition, we highlight that the mechanisms determining community structure change according to the spatial extent considered.

Three new free-living marine nematode species of Dorylaimopsis (Nematoda: Araeolaimida: Comesomatidae) from the South China Sea and the Chukchi Sea.

Three new species of the free-living marine nematode genus Dorylaimopsis are described from the South China Sea and the Chukchi Sea. Dorylaimopsis longispicula sp. n. is characterized by cuticle with lateral differentiation consisting of four longitudinal rows of larger dots in pharyngeal and tail regions, two rows of larger dots elsewhere, long curved spicules, and 12-16 tubular precloacal supplements. Dorylaimopsis boucheri sp. n. is characterized by lateral differentiation consisting of 3-4 longitudinal rows of larger dots in males and 4-6 rows in females, beginning about 30 µm posterior to amphids and terminating at the conical portion of the tail, 13-16 tubular precloacal supplements, and distal part of tail cylindrical without terminal setae. Dorylaimopsis jinyuei sp. n. is characterized by cuticle with lateral differentiation in the form of longitudinal rows of larger dots in two separate regions, not along entire body. One region is from posterior edge of amphid to anterior of intestine or anterior border of pharyngeal bulb in some females (4-7 longitudinal rows), the other is the tail region (5-7 longitudinal rows). In this paper, Dorylaimopsis metatypica Chitwood, 1936 is transferred to Hopperia because it is characterized by lateral differentiation consisting of larger, irregularly-distributed coarse dots (as in Hopperia), and Hopperia communis Gagarin Nguyen, 2006 is transferred to Dorylaimopsis based on the presence of longitudinal rows of coarse dots and a cylindrical buccal cavity in most specimens of this species. A dichotomous key to valid species of Dorylaimopsis Ditlevsen, 1918 is provided.

[Polychaete community in mangrove and salt marsh in Zhangjiang River Estuary, Fujian Province of East China].

In order to understand the community structure of polychaete in different botanic habitats in Zhangjiang River Estuary, an investigation was conducted in the habitats of Kandelia candel, Aegiceras corniculatum, Spartina alterniflora, and Avicennia marina in four seasons, 2010. A total of 15 polychaete species were recorded, and 6 species including Eteone delta, Namalycastis abiuma, Paraleonnates uschakovi, Polydora ciliata, Capitella capitata, and Mediomastus californiensis were found in the four habitats and four seasons. The density, biomass, richness index, evenness index, and diversity index of the polychaete had no significant differences among seasons but significant differences among habitats, and the dominant species of polychaete in S. alterniflora habitat differed from that in the other three mangrove habitats. Pearson correlation analysis showed that in the mangrove and salt marsh, there were no significant correlations between the polychaete parameters (density, biomass, richness index, evenness index, and diversity index) and the environmental factors (sediment temperature, salinity, total organic carbon, and total nitrogen), except that the species number of polychaete had significant correlation with sediment temperature due to the common species of polychaete such as Capitella capitata, Mediomastus californiensis, and Namalycastis abiuma in the mangrove and salt marsh in Zhangjiang River Estuary being of eurytherm and eurysalinity, and resistant to high organic matter content.

[Secondary productivity of macrobenthos in mangrove and salt marsh in Gaoqiao of Zhanjiang, Guangdong Province of South China].

In order to understand the secondary productivity of macrobenthos in different botanic habitats in intertidal zone in Gaoqiao of Zhanjiang, the Brey's empirical formula was applied to calculate the secondary productivity based on the investigations in the habitats of Sonneratia apetala, Aegiceras corniculatum, Sporobolus virginicus, and Bruguiera conjugate in four seasons, 2010. The secondary productivity of the macrobenthos in the habitats in four seasons was averagely 11.77 g AFDM x m(-2) x a(-1), being the highest in S. apetala habitat (18.16 g AFDM x m(-2) x a(-1)), followed by in A. corniculatum habitat (17.67 g AFDM x m(-2) x a(-1)), S. virginicus habitat (8.34 g AFDM x m(-2) x a(-1)), and B. conjugate habitat (2.92 g AFDM x m(-2) x a(-1)). The P/B ratio of the macrobenthos was the highest in B. conjugate habitat (2.38), followed by in S. virginicus, S. virginicus, and A. corniculatum habitats, with the values of 1.23, 0.99, and 0.48, respectively. The differences in the secondary productivity and P/B ratio of the macrobenthos among the four botanic habitats were mainly related to the sediment total organic carbon, food type, and macrobenthos individual size.

Contamination and potential biodegradation of polycyclic aromatic hydrocarbons in mangrove sediments of Xiamen, China.

Five stations were established in the Fenglin mangrove area of Xiamen, China to determine the concentrations of polycyclic aromatic hydrocarbons (PAHs) and the numbers of PAH-degrading bacteria in surface sediments. Assessing the biodegradation potential of indigenous microorganisms and isolating the high molecule weight (HMW)-PAH degrading bacteria was also one of the aims of this work. The results showed that the total PAH concentration of sediments was 222.59 ng g(-1) dry weight, whereas the HMW-PAH benzo(a)pyrene (BaP) had the highest concentration among 16 individual PAH compounds. The variation in the numbers of PAH-degrading bacteria was 2.62 x 10(2)-5.67 x 10(4)CFU g(-1) dry weight. The addition of PAHs showed a great influence in increasing the microbial activity in mangrove sediments. A bacterial consortium, which could utilize BaP as the sole source of carbon and energy, and which was isolated from mangrove sediments and enriched in liquid medium for nearly one year degraded 32.8% of BaP after 63 days incubation.

Distribution and sources of polynuclear aromatic hydrocarbons in Mangrove surficial sediments of Deep Bay, China.

Twelve sediment samples collected from three transects of mangrove swamp of Deep Bay, Shenzhen, China, were determined for polynuclear aromatic hydrocarbons (PAHs). The total PAHs concentrations ranged from 237 to 726 ng g(-1) dry weight, and showed strong correlation with total organic carbon (TOC), clay content and Pb concentrations. The highest PAHs concentrations were found in the samples from mangrove sediments. Overall, PAHs in Deep Bay sediment were lower than those in other developed areas. The biological effect due to PAHs alone in Deep Bay is expected to be low, based on the comparisons of individual and total PAHs concentrations determined in the sediment with those in USEPA sediment quality guidelines. Four and five-ring compounds dominated the PAHs composition pattern profiles. Principal component analysis (PCA) was applied to further investigate the source of PAHs. The PAH sources of Deep Bay mangrove swamp were suggested to be primarily combustion of fossil fuel, especially leaded-gasoline exhaust.