The co-occurrence of Artemia parthenogenetica and Branchinella spinosa (Branchiopoda: Anostraca) in a saline pond of south eastern Italy

The co-occurrence of Artemia parthenogenetica Bowen & Sterling, 1978 and Branchinella spinosa Milne-Edwards, 1840, was previously only supposed, on the basis of finding their cysts in the same lagoon, but active stages were never recorded together. In a saline lake in south eastern Italy, populations of the two species were observed for two years. A. parthenogenetica was typical of the early wet season (October–January), while B. spinosa, even if it was present before, developed in the late part of the wet season (February–May). Adult A. parthenogenetica were recorded only in the season 1999–2000. The seasonal distribution of A. parthenogenetica is probably controlled by abiotic conditions (i.e., photoperiod, temperature, conductivity, and rainfall); however, competition between specimens of similar body size (e.g., adults of A. parthenogenetica, and juveniles of B. spinosa) could explain the lower numbers of B. spinosa population in winter. The discovery of cysts of both species deep in the sediment of the lake suggests a long-lasting co-occurrence of these two Anostraca.     

Effects of floods on epilithon and benthic macroinvertebrate populations in an unstable New Zealand river

Temporal changes in epilithon biomass and benthic macroinvertebrate density were investigated in the Ashley River, a flood-prone river with an unpredictable discharge regime. Biomass, primary production and respiration of the epilithic community were highest in spring when filamentous algae were present and lowest following two large floods that occurred in close succession. Sixty invertebrate species were taken in benthic samples including 24 species of Trichoptera, 15 Diptera and 4 Ephemeroptera. Larvae of the mayfly Deleatidium (Leptophlebiidae) were numerically dominant and comprised up to 83 % of the fauna in any one month. Mean benthic invertebrate density was highest (9170–18 580 m^{–2) following long periods of low stable flow (< 30 m–3} s^–1) and lowest (230 m^–2) after a major flood (454 m^–3 s^–1). Reductions in benthic density occurred when flow exceeded about 30 m^–3 s^–1, the minimum discharge at which small cobbles are moved. Refuge seeking behaviours, flexible life histories and effective recolonization mechanisms enable the benthos of the Ashley River to persist and recover from frequent, temporally unpredictable disturbances.     

On the distribution patterns and population dynamics of sublittoral and profundal oligochaeta fauna from Lake Banyoles (Catalonia,NE Spain)

Oligochaeta assemblages from Lake Banyoles were composed of one species of Naididae and eight species of Tubificidae, Potamothrix heuscheri (8–1350 ind. m^–2) being the most abundant and widely distributed species, followed by Limnodrilus hoffmeisteri (25–858 ind. m^–2) and Psammoryctides barbatus (12–792 ind. m^–2). The remaining species were Potamothrix hammoniensis, Potamothrix bavaricus, Limnodrilus claparedeanus, Branchiura sowerbyi, Aulodrilus pigueti and Dero digitata, all of which occurred at lower densities and with restricted distributions.Regardless of sampling depth, maximum densities of oligochaetes were found in winter (up to 5,142 ind. m^–2 in December) and secondarily in June. Immature Tubificidae with hair setae and mature P. heuscheri were present and dominant throughout the year. Cestode parasites were recorded infesting L. hoffmeisteri and P. heuscheri populations.Oligochaeta densities increased with depth, but low oxygen concentrations (less than 1 mg l^–1) during a long period (4 months) in some basins of the lake acted as a key factor in reducing the density of worms and the species richness to one species, Potamothrix heuscheri.     

Ulva rigida (Ulvales,Chlorophyta) tank culture as biofilters for dissolved inorganic nitrogen from fishpond effluents

Ulva rigida was cultivated in 7501 tanks at different densities with direct and continuous inflow (at 2, 4, 8 and 12 volumes d^–1) of the effluents from a commercial marine fishpond (40 metric tonnes, Tm, of Sparus aurata, water exchange rate of 16 m³ Tm^–1) in order to assess the maximum and optimum dissolved inorganic nitrogen (DIN) uptake rate and the annual stability of the Ulva tank biofiltering system. Maximum yields (40 g DW m^–2 d^–1) were obtained at a density of 2.5 g FW 1^–1 and at a DIN inflow rate of 1.7 g DIN m^–2 d^–1. Maximum DIN uptake rates were obtained during summer (2.2 g DIN M^–2 d^–1), and minimum in winter (1.1 g DIN m^–2 d^–1) with a yearly average DIN uptake rate of 1.77 g DIN m^–2 d^–1 At yearly average DIN removal efficiency (2.0 g DIN m^–2 d^–1, if winter period is excluded), 153 m² of Ulva tank surface would be needed to recover 100% of the DIN produced by 1 Tm of fish.Abbreviations DIN= dissolved inorganic nitrogen (NH _inf4 ^sup+ + NO _inf3 ^sup– + NO _inf2 ^sup– ); - FW= fresh weight; - DW= dry weight; - PFD= photon flux density; - V= DIN uptake rate     

Biology ofChironomus piger Str. (Diptera: Chironomidae) and its role in the self-purification of a river

Chironomus piger larvae are widespread in small rivers and canals strongly polluted with domestic sewage. Despite this, almost nothing is known concerning the biology of the species under natural conditions and its role in the process of river self-purification. For two years, benthic samples were collected in the Sestra River at a site about 250 m downstream of the effluent discharge drains of a sewage treatment installation where the greatest concentrations of the larvae occurred. The number and biomass ofC. piger larvae were subject to marked fluctuations,viz. 96,000–348,000 ind m^–2 and 420–1,800 g m^–2. 460 degreedays (on average) was required for development of one generation.C. piger has 5 or 6 generations per year depending on the hydrometeorological conditions during the growing season.C. piger larvae play an important role in self-purification of the river. They utilize precipitating seston for food and for building their dwelling tubes. According to our calculations the amount of organic matter assimilated in the area of maximum larval concentration ranged 80–177 g wet weight m^–2 day^–1, and 32–71 g wet weight m^–2day^–1 was mineralized.     

Dormant egg bank characteristics and hatching pattern of the Phallocryptus spinosa (Anostraca) population in the Makgadikgadi Pans (Botswana)

The anostracan Phallocryptus spinosa has an almost exclusively palearctic distribution. The Makgadikgadi Pans area in Botswana represents the only distribution record south of the Sahara. In this ephemeral wetland, it is an important food item in the diet of migrating birds. By studying egg bank characteristics (such as depth and density) and hatching requirements, we investigated the persistence of this sub-Saharan population. At localities in the middle and north basin of Sua Pan, sediment cores were taken along a transect, and dormant eggs were isolated. Densities of the active dormant egg bank ranged from 833 to 31449 dormant eggs m⁻², indicating that this species is well established. Most of the dormant eggs were found in the top 4 cm of the sediments, and densities decreased to zero at a depth of 13 cm. Considering the expected low sedimentation rate, the presence of dormant eggs down to 13 cm indicates long-time occurrence of P. spinosa in the Makgadikgadi Pans area. We observed high hatching fractions (up to 85%) at a temperature of 22 °C and a salinity of 5 ppt. A second anostracan species, Branchinella ornata, co-occurred with P. spinosa in our study site. This population also had a large active dormant egg bank (ranging from 6634 to 50557 dormant eggs m⁻²) with dormant eggs present until a depth of about 11 cm. This pattern indicates a long-time co-occurrence of P. spinosa and B. ornata.     

High-latitude<Emphasis Type="Italic"> Acropora cervicornis</Emphasis> thickets off Fort Lauderdale,Florida, USA

Baseline studies conducted in 1998 document the presence of robust, non-reef-building Acropora cervicornis thickets in shallow (3–7 m depth), near-shore waters off the coast of Fort Lauderdale, Florida, USA. These thickets thrive in a high-latitude environment, the northernmost in the continental USA, in the midst of potential anthropogenic stressors. Within thickets, the spatial variation in mean percent coral cover, macroalgal cover, scleractinian species richness, density of A. cervicornis juveniles, and the density and size of A. cervicornis colonies and fragments were recorded. Thicket size ranged between ~0.1 and 0.8 ha and mean coral cover varied between ~5 and 28%, with A. cervicornis accounting for ~87–97% of all scleractinians. Mean A. cervicornis colony and fragment densities per thicket were 1.3–3.3 colonies m^–2 and 0.7–2.8 fragments m^–2, respectively. Recruit densities varied between 0 and 1 ind. m^–2. White band disease was detected at all thickets, with a mean A. cervicornis colony surface area affected of 1.8%. For all thickets, densities of the corallivorous polychaete Hermodice carunculata ranged between ~18 and 86 ind. ha^–1, with predation scars affecting <0.2% of the A. cervicornis cover. These flourishing A. cervicornis thickets off Fort Lauderdale provide an interesting counterpoint to the declining and disease-stricken A. cervicornis populations reported in the Florida Keys and wider Caribbean.     

Occurrence of Diaphanosoma excisum (Sars) on a sandy beach at Balramgari (Orissa), India

The occurrence of Diaphanosoma excisum (Sars), a freshwater cladoceran, in benthic samples of an intertidal sandy beach is reported. Population density was seasonal. A relatively high density was recorded from June to September (south-west monsoon season) with a maximum (46 ind 10 cm^–2) in September at a depth of 10–15 cm of sediment. A sudden decline occurred during north-east monsoon (October to January), and in the fair season (February to May), the cladocerans disappeared. Mean density varied (P<0.001) with sediment depth and season and showed a contagious dispersion. Abundance was negatively correlated with salinity (r = –0.76) but positively with POC (r =0.79) and mean grain size of the sediment (r = 0.93). The density of D. excisum was highest in fine sand.     

Population dynamics of alien gammarid species in the River Odra estuary

During the period of 1988–2000, three alien gammarid species, i.e. Gammarus tigrinus Sexton, 1939, Pontogammarus robustoides G. O. Sars, 1894, and Dikerogammarus haemobaphes (Eichwald, 1841) were recorded in the Odra estuary. This study, the first record of G. tigrinus and P. robustoides in Poland, focuses on the distribution, abundance, and biomass as well as on population structure of the three new species found in the coastal zone of the estuary. G. tigrinus and P. robustoides were first sampled in the Szczecin Lagoon (mid-part of the estuary) in 1988. The densities of both species were high from the time they were first recorded and exceeded 10 000 ind. m^–2, while the biomass was 25 and 140 g m^–2, respectively. G.tigrinus occurred at higher densities in northern and eastern parts of the Lagoon, while P. robustoides was particularly abundant in the south-eastern part, most heavily affected by River Odra discharge. In 1999, the third gammarid, D. haemobaphes, was recorded in the southern part of the estuary. Both in 1999 and 2000, the species was found in qualitative samples (dredge collections of Dreissena polymorpha) taken from the western branch of the river. As estimated from quantitative samples, densities and biomass in the eastern branch were rather low and did not exceed 150 ind. m^–2 and 2.7 g m^–2, respectively. The Szczecin Lagoon population of G. tigrinus produces at least two generations within a year: a summer one and an overwintering one. The latter is dominated by older and larger specimens. The species may reproduce in the Lagoon from April until November.     

Life history,population dynamics and production of Pontoporeia hoyi (Crustacea,Amphipoda) in relation to the trophic gradient of Lake George,New York

The life history characteristics, population dynamics and production of Pontoporeia hoyi in Lake George, New York, were studied from May 1981 through October 1982. P. hoyi, in terms of both density and standing crop, is the most prevalent member of the deep water macrobenthos of Lake George. It reproduces in the winter, with young being released in the late winter-early spring. At the southernmost study site, young released in the spring grew to 6–7 mm in length and bred during their first winter. At the remaining sites, P. hoyi required two years to complete its life cycle. This difference in life history characteristics can be related to food availability and temperature differences. The open waters of the south end of Lake George are not only more productive but are also more closely associated with the littoral zone, providing a wealth of bacteria-rich detritus for benthic deposit feeders. The greater food availability in the south basin of Lake George is reflected in significantly larger brood sizes and smaller size at maturity for P. hoyi populations from the south end of the lake.The southernmost study site has significantly greater P. hoyi density and standing crop than all other sites. The cohort of the year dominated density and standing crop at the southern site while the cohort of the previous year dominated standing crop at the other sites. Peak abundance ranged from 600 · m^–2 at the north site to 2 900 · m^–2 at the south site. Cohort production ranged from 2g · m^–2 at the north site to 15g · m^–2 at the south site.     

Effect of Aeolosoma sp. (Aphanoneura: Aeolosomatidae) on the Population Dynamics of Selected Cladoceran Species

Although oligochaete worms naturally coexist with cladocerans in many shallow freshwater ponds and lakes, their influence on the latter is not well established. In this work we studied the effect of Aeolosoma sp. on the population growth of Alona rectangula, Ceriodaphnia dubia, Daphnia pulex, Macrothrix triserialis and Moina macrocopa. Population growth studies were conducted at one algal food density (1 × 10⁶cells ml^–1 of Chlorella vulgaris). The experimental design was similar for all five cladoceran species, where we used 100 ml capacity transparent jars containing 50 ml of EPA medium with the desired algal density and three replicates for each treatment. The test medium was changed daily and fresh algal food was added. The initial density of each of the cladoceran species in the population growth studies was 0.4 ind ml^–1 while that of the worms 1.0 ind ml^–1. Following inoculation, we estimated daily the number of cladocerans and the worms for duration of 21 days. Regardless of the presence of worms, Moina macrocopa and Macrothrix triserialis showed rapid population growth while A. rectangula took more than 2 weeks to reach peak abundances. With the exception of M. triserialis, all the other our cladoceran species declined in the presence of Aeolosoma sp. The lowest peak population density (about 1 ind ml^–1) was observed for M. triserialisin controls. The remaining species had peak densities of about 3–5 ind ml^–1. The rates of population increase per day varied from 0.03 to 0.19 depending on the cladoceran taxa and the treatment. In general we found that pelagic taxa were more adversely affected by the presence of the worms than were the littoral cladocerans.     

Secondary production of Rhyacophila minora,Ameletus sp., and Isonychia bicolor from streams of low and circumneutral pH in the Appalachian Mountains of West Virginia

We estimated the secondary production of Rhyacophila minora, Ameletus sp., and Isonychia bicolor in three acidic streams and one circumneutral stream in Randolph County, West Virginia. Quantitative benthic samples were collected monthly from these second-order streams from November 1990 to October 1991. Mean pH values in the acidic streams were 4.5, 4.8, and 4.8, and mean pH in the circumneutral stream was 6.7. Production estimates for Rhyacophia minora in the acidic streams were 49.6, 19.2, and 15.8 mg m^–2 y^–1. Production of R. minora in the circumneutral stream was 1.0 mg m^–2 y^–1. Ameletus sp. production estimates for the acidic streams were 144.8, 176.8, and 208.3 mg m^–2 y^–1. Ameletus sp. production in the circumneutral stream was 7.4 mg m^–2 y^–1. Secondary production of I. bicolor in the circumneutral stream was 116.6 mg m^–2 y^–1. No Isonychia were collected from the acidic streams. The higher production of R. minora and Ameletus sp. in the acidic streams may be associated with differences in macroinvertebrate community structure.     

Diurnal vertical distribution of rotifers (Rotifera) in the Chara zone of Budzyńskie Lake,Poland

Diurnal vertical distribution of rotifers was investigated in the Chara bed and the water immediately above it in the shallow region (ca. 1 m depth) of Budzyskie Lake (Wielkopolski National Park, Poland) in early September 1998. Eighty one rotifer species were identified – 71 among Chara and 59 in the open water. Significant differences in rotifer densities were observed in the Chara, with highest numbers during the day (2316 ind. l^–1) and lowest numbers early morning (521 ind. l^–1) and at dusk (610 ind. l^–1). Above the Chara, the numbers of rotifers did not change significantly (615–956 ind. l^–1). Littoral- or limnetic-forms differed in their diel vertical distribution between both zones. One group of littoral species was characterized by increased densities in the Chara in the daytime, while a second group increased in density during the night. The densities of limnetic species, which were much higher in open water, decreased in the morning or daytime in this zone. These differences in the diel behaviour of particular groups of rotifers may be dependent on microhabitat and may also be related to different kinds of predation, the exploitative competition for shared food resources between rotifers and crustaceans, as well as typical adaptation to littoral or limnetic life.     

Combined effects of temperature,food (<Emphasis Type="Italic">Chlorella vulgaris</Emphasis>) concentration and predation (<Emphasis Type="Italic">Asplanchna girodi</Emphasis>) on the morphology of <Emphasis Type="Italic">Brachionus havanaensis</Emphasis> (Rotifera)

The combined effect of temperature, food level and the presence of an invertebrate predator on the body size of the rotifer Brachionus havanaensis were tested in this study. B. havanaensis was cultured at 15, 20, and 25°C under three different Chlorella vulgaris levels (0.5 × 10⁶, 1.0 × 10⁶ and 2.0 × 10⁶ cells ml⁻¹) in the presence and in the absence of Asplanchna girodi. For each treatment we maintained three replicates and constant (0.4 ind ml⁻¹) population density of B. havanaensis. In treatments containing A. girodi, the predator was separated from the prey by a mesh (pore size 50 μm). On the last day of the experiment, a portion of the B. havanaensis population was sampled for several morphometric measurements (adult lorica length, width, posterior spine length, body volume, and the egg volume). Size measurements were done by drawing the specimens using a calibrated camera lucida. Statistically significant impact of temperature as well as the predator’s presence was observed on the lorica length, posterior spine, and egg volume of B. havanaensis. The interactions of food × temperature, or predator′s presence × food × temperature were non-significant (P > 0.05) for lorica length, spine length, body volume, and egg volume. Regardless of the type of treatment, there was a direct positive correlation between lorica length and width. Egg volume was linearly related to the adult size. Notably long posterior spines were observed in treatments containing the presence of A. girodi. Guest editors: S. S. S. Sarma, R. D. Gulati, R. L. Wallace, S. Nandini, H. J. Dumont & R. Rico-Martínez. Advances in Rotifer Research     

Bioturbation by Nereis sp. and its effects on the phosphate flux across the sediment-water interface in the Palmones River estuary

The effects of Nereis sp. on the flux of dissolved phosphate across the sediment-water interface has been studied in Palmones River estuary using benthic flux-chambers and intact cores. Diffusive fluxes of phosphate were calculated from pore water gradient concentration and compared with those obtained from benthic chambers experiments. The high abundance of Nereis in the upper sediment layers appears to play an important part in the dissolved oxygen profiles in the overlying water, but had no effect on the redox potential. A negative relationship was found between the Nereis abundance and the phosphate gradient; this gradient ranged between 40 µmol 1^–1 cm^–1 with 340 Nereis individuals m^–2 and 20 µmol 1^–1 cm^–1 with 900 Nereis individuals m^–2. The ratio of the in situ flux to the flux gradient concentration for dissolved phosphate increased with the abundance of Nereis (from 1.7 at low abundance to 5.8 at high abundance).     

Trophic significance of herbivorous macroinvertebrates on the central Great Barrier Reef

The common herbivorous macroinvertebrates on reef flats of the central Great Barrier Reef (GBR) were, in order of abundance: gastropod molluscs (Turbo and Trochus spp.); pagurid crabs; and the starfish, Linckia laevigata. The density of macroinvertebrates on Davies Reef was lowest in the thick-turf habitats at the windward reef-crest (0.6–0.9 m^–2) compared with 3.1 to 5.2 m^–2 elsewhere on the reef flat. Invertebrate grazer densities were similar on mid-shelf reef flats (mean: 2.3–3.6 m^–2) and significantly lower on outer-shelf reefs (0.3–1.0 m^–2). The ingestion rate of Turbo chrysostomus, the most abundant macroinvertebrate species, was derived from (a) faecal production and food absorption efficiency, (b) comparison of algal biomass on grazed and ungrazed natural substrata and (c) gut-filling rate and feeding periodicity in field populations. The ingestion rate of Trochus pyramis, the most common trochid and an abundant component of the macroinvertebrate fauna, was also estimated using (a). This gastropod fed continuously, whereas T. chrysostomus showed a distinct nocturnal feeding periodicity. T. chrysostomus and T. pyramis ingested daily means of 35 and 54 mgC animal^-1, respectively. Total gastropod grazing rates (mgC m^–2d^-1 in the field ranged from 11 in a thick-turf, reef-crest habitat to 144 on the open-grazed main flat. Grazing by gastropods accounted for between 0.3 and 8% of the net production of benthic algal food resources, depending on location on the reef flat. Across the whole reef flat the mean (areally-weighted) gastropod grazing rate was 6% of net production. A comparison of the relative roles of different types of grazers led to the conclusion that fishes are likely to have the greatest overall trophic impact on reefs of the central GBR. Even where macroinvertebrates are most abundant on reef flats, the yield from benthic algal communities to macroinvertebrates is estimated to be only one third of that due to fishes.Contribution no. 471 from the Australian Institute of Marine Science     

Distribution and production ofChironomus salinarius (Diptera: Chironomidae) in a shallow coastal lagoon in the Bay of Cádiz

The abundance, generation time and production ofChironomus salinarius larvae in a lagoon fish-pond system in the Bay of Cádiz were studied by taking monthly samples at 3 sites during 1991 and 1992. Numerical abundance and biomass of larvae showed considerable spatial, seasonal and interannual variation (ANCOVAs,P<0.001). The maximum mean annual density was 7048 larvae m^–2, and corresponded to a biomass of 3.08 g dry weight (DW) m^–2. It was recorded at the site with the lowest rate of water renewal. Seasonal patterns were similar at all sites, with main annual peaks of abundance and biomass in autumn-early winter. Chironomid density was positively related to the biomass of benthic macroalgae (P<0.001). The population studied was multivoltine with a probable average of five generations per year, with overlapping cohorts and a predominance of third- and fourth-instar larvae. Estimates of annual production ranged between 72.2 g DW m^–2 yr^–1 at the site with the lowest rate of water renewal in 1991 and 0.1 g DW m^–2 yr^–1 at the site with the highest rate of water renewal in 1992. Mean annual production and the production/biomass ratio for the system was estimated to be 16.8 g DW m^–2 yr^–1 and 12.7, respectively. Possible factors leading to the observed density fluctuations are discussed, as well as possible sources of error in production estimates.     

Artemia monica cyst production and recruitment in Mono Lake,California, USA

Annual egg production was determined for Artemia monica in Mono Lake, California, from 1983 to 1987. Annual oviparous (overwintering cyst) production was 3 and 7 million cysts m^–2 yr^–1 in 1986 and 1987, respectively, as measured by in situ sediment traps. Cyst production for the entire five year period was calculated using Artemia census data and inter-brood duration derived from mixolimnetic temperature. These estimates ranged from 2 to 5 million cysts m^–2 yr^–1. This method underestimated annual production by 30%, when compared to estimates using sediment traps. Cyst production was similar during 1983–1986 and showed a significant increase in 1987, which was due primarily to a larger reproductive population later in the year. Recruitment into the adult populations of the following spring ranged between 1.4 to 3.2%. Overall abundance of this generation reflected the patterns in annual cyst production. Compensatory effects must operate on the second generation of each year, since summer populations were similar in all years despite differences in cyst production.     

Influence of environmental factors on the production of Potamothrix alatus paravanicus Poddubnaya & Pataridze (Tubificidae) in different areas of Lake Sevan

A modification of the Hynes' method was used to estimate production of Potamothrix alatus paravanicus Poddubnaya & Pataridze (Tubificidae), the dominant species of benthic invertebrate in Lake Sevan. Maximum production (5–24 g m^t\-2 wet weight) occurred in the sublittoral, while maximum biomass was found (8–17 g m^–2 wet weight) in the profundal. The turnover ratio of the average cohort varied between 2.4 and 5.0. The annual turnover ratio (P/B) decreased from 2.1–3.1 in the littoral to 0.1–0.4 in the profundal zone.A logarithmic correlation was found between P/B and temperature and oxygen regime, and depth and average size of clitellate specimens.     

Effects of outbreak of the train millipede Parafontaria laminata armigera Verhoeff (Diplopoda: Xystodesmidae) on litter decomposition in a natural beech forest in Central Japan. 1. Density and biomass of soil invertebrates

Soil invertebrates were studied to determine the animals important in litter decomposition and soil formation in a natural forest of Fagus crenata Blume mixed with Quercus mongolica var. grosseserrata Rehd. et Wils., where outbreak of the adult train millipede, Parafontaria laminata armigera Verhoeff was recorded in 1980. The density and biomass of soil invertebrates, and their distribution in soil, were surveyed largely by hand sorting and also using Tullgren and Baermann apparatuses. The densities of soil macroinvertebrates were 10²–10³ individuals/m². Diplopoda was the most abundant among them, 87.3% of which was the train millipede. The total biomass in wet weight of soil macro-invertebrates was 34.9–70.5g/m² in 1980–1981, when the millipede was pre-adult or adult, and it decreased to 3.5–6.7g/m² in 1982–1984, when it was young. The density of soil invertebrates extracted by apparatuses was 10⁴–10⁶ individuals/m². The total biomass of these was estimated to be 5.8–10.8g/m². The majority of soil invertebrates lived in the A₀ horizon, whereas the train millipede lived in soil of the A₁+A₂ horizon. These results suggest that the train millipede is one of the most important soil invertebrates affecting soil properties. For evaluating the importance of the species, more than 8 years survey of hand-sorting together with the Tullgren apparatus was necessary, as the train millipede grew synchronously and had an 8-year life span and young stages of 1.5–3.5mm long.