A model approach to evaluate the effect of temperature and food concentration on individual life-history and population dynamics of Daphnia

Abstract The majority of sediment-dwelling foraminifera are thought to be deposit feeders. They use their reticulopodia to gather sediment with associated algae, organic detritus, and bacteria. Uptake of diatoms by foraminifera have been observed but rarely quantified. We measured the clearance (gathering) rate and ingestion rate of diatoms by the common benthic foraminifer Quinqueloculina seminula using Nitzschia closterium as prey under laboratory culture conditions. Grazing experiments were performed to evaluate the effects of temperature (at 12, 15, 18, 21, and 24°C) and food availability (10 to 800 cells mm−2) on uptake rates of diatoms. The clearance rates, estimated from the disappearance of food items, were variable (0.59–4.4 mm2 foram−1 h−1) and did not show a clear relationship with food availability. The maximum clearance rates increased from 1.80 ± 0.21 to 2.69 ± 0.32 mm2 foram−1 h−1 when temperature increased from 12 to 18°C and decreased to 2.28 ± 0.25 mm2 foram−1 h−1 at 24°C. Ingestion rates varied from 1.0 to 43 × 103 diatoms foram−1 h−1, following a hyperbolic response to food concentrations at all experimental temperatures. The maximum individual ingestion rates increased from 842 ± 180 to 1648 ± 480 (mean ± SE) cells foram−1 h−1 and then decreased to 316 ± 54 cells foram−1 h−1 as temperature increased from 12 to 24°C. Experimental results revealed that 12–18°C was the optimal temperature range for Q. seminula feeding for specimens adapted to local conditions. Our study indicates that Q. seminula plays an ecological role by feeding upon benthic diatoms in marine benthic ecosystems.

Download Full-text

Population dynamics of Stenothoe valida Dana, 1852 (Amphipoda, Stenothoidae) at Cheongsapo beach of Busan, Republic of Korea

Crustaceana ◽

10.1163/15685403-bja10105 ◽

2021 ◽

Vol 94 (4) ◽

pp. 413-429

Author(s):

Ye Ji Lee ◽

Won Gyu Park

Keyword(s):

Population Dynamics ◽

Life History ◽

Sex Ratio ◽

Brood Size ◽

Ovigerous Female ◽

Seasonal Pattern ◽

Recruitment Rate ◽

Republic Of Korea ◽

Female Size ◽

History Of

Abstract The population dynamics of Stenothoe valida Dana, 1852 were studied at Cheongsapo beach of Busan, Republic of Korea, from March 2019 to March 2020. Sampling was conducted once a month at low tide during spring tides. Specimens were grouped by the cephalic length at 0.025 mm intervals, and classified into four categories: females, ovigerous females, males and juveniles. The sex ratio, defined as females : total males + females, exceeded 0.5 during most of the study period. Brood size was significantly coupled with ovigerous female size. Two to four cohorts appeared at each study period. New cohorts occurred at almost every sampling except in the samples Jun-2, and Nov-2. Life span was estimated at 1-2 months. The juvenile ratio, the ratio of ovigerous females, and the recruitment rate estimated by FiSAT were commonly high in summer and winter. The life history of S. valida was not coupled with water temperature, but had a strong seasonal pattern.

Download Full-text

Size-specific sensitivity of cladocerans to freshwater salinization: Evidences from the changes in life history and population dynamics

Environmental Pollution ◽

10.1016/j.envpol.2021.118770 ◽

2022 ◽

Vol 296 ◽

pp. 118770

Author(s):

Jing Huang ◽

Yurou Li ◽

Yunfei Sun ◽

Lu Zhang ◽

Kai Lyu ◽

...

Keyword(s):

Population Dynamics ◽

Life History ◽

Specific Sensitivity ◽

Freshwater Salinization

Download Full-text

Larval density, temperature and biological aspects of Chrysomya megacephala (Diptera: Calliphoridae)

Arquivo Brasileiro de Medicina Veterinária e Zootecnia ◽

10.1590/s0102-09352006000400018 ◽

2006 ◽

Vol 58 (4) ◽

pp. 562-566 ◽

Cited By ~ 7

Author(s):

C. Reigada ◽

W.A.C. Godoy

Keyword(s):

Population Dynamics ◽

Life History ◽

Body Size ◽

Larval Density ◽

Chrysomya Megacephala ◽

Life History Characteristics ◽

Two Temperatures ◽

Biological Aspects ◽

Experimental Populations ◽

Simultaneous Influence

The effect of larval density on the survival, fecundity and body size at two temperatures in experimental populations of C. megacephala was studied. No effect from simultaneous influence of density and temperature on life history characteristics of C. megacephala was found. Significant effects of density and temperature on survival, fecundity and body size were observed. The importance of these results for the population dynamics of C. megacephala is discussed.

Download Full-text