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A systematically comparative study on community structure of macrozoobenthos betweena a typical macrophytic lake, Lake Biandantang and a typical algal lake, Lake Houhu, was carried out from April, 1996 to March, 1997. The results showed that the species number, biodiversity, abundance and biomass of macrozoobenthos community in Lake Biandantang were much higher than those of macrozoobenthos in Lake Houhu; species composition and functional feeding groups were also prominently different, the similarity coefficient of macrozoobenthos communities in the two Lakes was about 0. 30;in Biandantang Lake, scrapers were dominant in abundance and biomass, while in Houhu Lake, direct -collectors were dominant in number. These all probably were due to the presentation of higher aquatic macrophytes, especially those submerged ones, which provide various habitats and niches for more species, at the same time, keep the aquatic ecosystem complex, spatially heterogeneous and functionally stable.

The energy flow ofBranchiura sowerbyi was studied for the first time in China in a shallow macrophytic lake, Biandantang Lake, Hubei Province. The energy flow was calculated from the measurement of flesh production (12.5241kJ/m2a), egestion (517.7302kJ/m2a), metabolism (38.3273 kJ/m2a), and excretion (4.3798kJ/m2a). The net growth efficiency of the species is about 22.7%, which accords well with the generally reported value for oligochaetes. In addition, the relationship between starvation respiration (R, mgO2/ind·d), wet weight (Ww, mg) and temperature (T, °C) were also measured, with the regression function beingR=0.008Ww0.736 e0.050T.

Energy flow of the macrozoobenthic community in an algal lake, Houhu Lake (Wuhan, China) was investigated from April, 1996 to March, 1997. The estimated consumption of the community was 2522.7 kJ/(m2·a); defecation was 2049.1 kJ/(m2·a); metablism 371.2 kJ/(m2·a); excretion 34.7 kJ/(m2·a) and production 67.7 kJ/(m2·a). The assimilation rate of the community was 19%; and 81% of its ingestion was defecated. The computed net growth efficiency was 14%, much lower than most reported values, which meant that the macrozoobenthic community in Houhu Lake utilized food less effectively.

The production of Sphaerium. lacustre in Lake Houhu was estimated by two methods. The results were: 1.048 g/(m2a) of fresh weight with shell or 0.0599g/(m2a) of dry weight shell-free by size-frequency method; 1.178 g/(m2a ) of fresh weight with shell or 0.0673 g/(m2a) of dry weight shell-free by instantaneous growth method. The corresponding P/B ratio were 3.23.4, respectively. Thus, the results by the two methods are coincided each other.

April, 1996 to March, 1997 studies on the abundance and secondary production ofLimnodrilus hoffmeisteri in an algae-dominated lake showed that the worn density and biomass peaked in December at 152 ind/m2 and 0.087 g/m2, respectively. The secondary production of the animal was 0.294 g/m2 fresh wt/a. The turnover rate (P/B ratio) was 11.4.

The energy budget ofBellamya earuginosa in a shallow algal lake, Houhu Lake (Wuhan, China) was investigated by the measurement of flesh production (32.8 kJ/(m2·a)), egestion (337.7 kJ/(m2·a)), metabolism (246.7 kJ/(m2·a)), and estimation of excretion (21.4kJ/(m2·a)). The net growth efficiency of the species is about 10.9%, which accords with the generally reported value for gastropods. In addition, the relationships between starvation respiration (R, mgO2/(Ind·d)), body weight (Wd, mg in dry wt) and temperature (T, °C) were also determined. The regression equationR=0.044Wd 0.537 e 0.061T was obtained by the least square method, The measured SDA of the species is 26.51% of its gross metabolism.

Shallow lakes numerously distributed along mid lower reaches of the Yangtze River are of great importance to human life. Among those lakes, molluscan species are abundant, especially the endemic ones. This paper presents the results of the investigation of Mollusca in 13 lakes and 110 species belongingn to 15 families and 40 genera were recorded. Among them, Bellamya quadrata (Benson), Bellamya aeruginosa (Reeve), Alocinma longicornis (Benson), Parafossarulus sinensis (Neumayr), Parafossarulus eximius (Frauenfeld), Semisulcospira cancellata (Benson), Radix auricularia (Lin.), and Radix plicatula (Beuson) in Gastropoda and Limnoperna lacustris (Martens) Lanceolaria grayana (Lea), Anodonta woodiana woodiana (Lea), Cristaria plicata (Leach), Corbicula fluminea Muller and Sphaerium lacustre (Muller) in Bivalvia were predominant. The species number( S )-area( A, km 2) relationship of Mollusca was calculated. It may be expressed as: lg S =0.767+0.258lg A . By means of cluster analysis method, the faunal similarities of Mollusca among 13 lakes were also analyzed. They can be divided into three groups: Group one consists of those in Poyang Lake and Dongting Lake that are the largest lakes in China and connected directly with the Yangtze River. Group two includes molluscans in 10 lakes of middle or small sizes, all with abundant aquatic vegetation. Group three contains only the fauna of Taihu Lake located near the lower Yangtze River and characterized by its abundant bivalves.

An investigation on one of the dominant species of gastropods, Bellamya aeruginosa in Houhu Lake, Wuhan was carried out from April, 1996 to March, 1997. The results showed that the population was composed of three year classes, among which the 96 year class grew most quickly, with instantaneous growth rate of dry weight (unshelled) 2. 80. The annual production of the animal calculated by instantaneous growth rate method was: wet weight, 33. 13 g m-2 a-1; dry weight (unshelled), 1. 932 g m-2 a- 1. The corresponding annual P/B ratios was 0. 85.

Annual production and life cycle of five dominant species of Chironomidae (Chironomus plumosus, Cryptochironomus sp.,Tokunagayusurika akamusi, Procladius sp.,Clinotanypus sp.) were studied with samples collected monthly from April, 1996 to March, 1997 in Houhu Lake at four stations. Based on instar-frequency data,C. plumosus was univoltine, while the other four were bivoltine. Production rates in grams wet weight m−2a−1 calculated by the size-frequency method wereC. plumosus, 2.170;Cryptochironomus sp., 0.602;T. akamusi, 3.160;Procladius sp., 0.964;Clinotanypus sp., 0.390. Their P/B ratios were 3.9, 4.9, 4.4, 5.3 and 6.6, respectively.

A comparative study on annual production of macrozoobenthos community was carried out in a typical algal lake-Lake Houhu and a typical macrophytic lake-Lake Biandantang.The results showed that the annual pro-duction of macrozoobenthos community in Lake Biandantang(38.926g/(m 2 ·a))was a bit lower than that of Lake Houhu(47.505g/(m 2 ·a)).The eutrophication of Lake Houhu,slightly higher than that of Lake Biandantang,which was much fitter for the growth of pollution-prone species of oligochaetes,resulted in more oligochaete production.Algal lakes bearing preferable situations for the existence of omnivorous gastropods like B.aeruginosa attained higher gastropod production.Large chironomids usually present weed-free,higher entrophication water body,which match the conditions of Lake Houhu,so Lake Houhu liad larger production of chironomid.Nev-ertheless,the proportions of macrozoobenthic production contributed by chironomids,oligochaetes and gas-tropods remained fairly stable,which were14%-15%,7%-8%,77%-79%,respectively.

Sixteen species of marine Oligochaeta (8 Tubificidae, 1 Naididae, 6 Enchytraeidae, 1 Megascolecidae) are recorded from the Qingdao area, at about 36° N on the Chinese Yellow Sea coast. Taxonomic remarks are given for most species, of which none appears new to science.Limnodriloides victoriensis Brinkhurst & Baker andEnchytraeus kincaidi Eisen, previously known from the Northeast Pacific, are described from Asia for the first time. These, as well asMonopylephorus rubroniveus Levinsen and aLumbricillus sp., are interpreted as members of a temperate fauna, while all the remaining species have previously been reported from Hong Kong (at about 22° N) and thus are regarded as subtropical/tropical forms in the Yellow Sea.

Limnodrilus amblysetus sp.nov. (Tubificidae) is described and compared with other Chinese Limnodrilus species as well as Limnodrilus silvani which is recorded from California and Oregon, U.S.A. The presence of other previously known Chinese species is confirmed. Polymorphism in the development of dorsal chaetae, already known for the Naididae and for Tubificinae (Tubificidae), is now suspected for Rhyacodrilinae (Tubificidae). The oligochaete fauna of China resembles that of India, Japan,and the eastern Soviet Union. Some tropical and subtropical Naididae may yet be discovered from the southern provinces, some cold-water Tubificidae and Lumbriculidae from the northeast and those elevated parts of the far west of China that are not deserts.

Tylopharynx clariamphida sp. n. is described from muddy sand collected in Anhui Province, China. It can be distinguished from T. foetida (Bütschli, 1874), the type and only species of the genus, by numerous characters: having 24 to 26 prominent and clearly separated longitudinal ridges, a higher lip region with no hint of a cephalic framework, more prominent amphidial foveae in lateral view, wider and more posteriorly located amphidial apertures, smaller basal knobs of stoma, longer metacorpus, more enlarged phasmids, shorter spicules with shorter digitate terminus, shorter reflexed part of testis, and thicker gubernaculum with more angular shape. For comparison, an expanded description is given for T. foetida from Belgium, and SEM photographs of both species are provided.

For the purpose of fishery development, a hydrobiological investigation of Lake Chenhu was carried out in 1983 with reference to the productivity of various food organisms as well as fish. Of the entire lake, the annual net primary production was determined to be 27,818×106 kcal for phytoplankton, 2,898×106 kcal for macrophytes and 64,840×106 kcal for wet land vegetation. The annual secondary production chiefly from gastropods was 2,632×106 kcal. On the basis of 1981–1982 fishery data, the production of the main stocked fishes in the lake was also roughly computed. Analysing all obtained production data, we find the energy conversion rate of food organisms to fish in the water at the present stage is fairly low. Even in 1982, the year of better fishery management, food energy converted to plankton feeders or herbivores was only 1.6–1.8%; energy converted to fish yield was even lower, only 0.2–0.8%. To get a potential fish output of the ecosystem, a tentative estimation of fishery capacity of Lake Chenhu was made by using the index of food quotients and relevant conversion factors. The theoretical fish production in the lake is estimated to be around 6,000 t and, through the improvement of fishery management, an annual fish yield of 2,000 t can be expected.

Branchiura sowerbyi in the Donghu Lake (Wuhan, China) completes its life cycle in one year. Its production rates were 6.7 g m−2 yr−1 (wet weight) during the period from April 1962 to May 1963 and 8.6g m−2 yr−1 during the period from August 1963 to August 1964. The standing stocks in corresponding periods were 1.9g m−2 (wet weight) and 1.1g m−2, and theP/B ratios were 3.6 and 7.8. Based on the standing stock during 1973–1975, an evaluation of recent productin levels ofB. sowerbyi in Donghu Lake has also been made (i.e. 5.7–33.5g m−2 yr−1).

[This corrects the article DOI: 10.1016/j.omtn.2018.01.001.]., (© 2023 The Author(s).)