Reduction in clearance rate was observed in the mussel Choromytilus chorus in relation to the degree of environmental pollution. Three sampling sites included the polluted San Vicente Bay, middling polluted Corral Bay, and weakly polluted Yaldad Bay in southern Chile. Pollution levels were estimated by quantitative analysis of polynuclear aromatic hydrocarbons (PAHs) in mussel tissue from the three sites. Mussels from San Vicente showed lowest clearance rates and highest PAHs levels in both spring 1998 and summer 1999. Populations from Corral and Yaldad showed generally low levels of PAHs, so the mussels from Yaldad showed the highest rates of clearance in comparison to Corral and San Vicente populations. The significant negative relationship (P < 0.001) demonstrated between tissue pollution of the mussels and their clearance rates argues for the usefulness of the method employing a non-destructive biomarker in evaluation of the impact of environmental pollution on marine species.
performed at the end of the rainy season. At each site were established three linear transects of 40 m, in which five monoliths were extracted according to protocol of "Tropical Soil Biology and Fertility". The macroinvertebrates were extracted in situ and the same time was evaluated vegetal structure and was analyzed the fertility of soil. The highest density of organisms collected was the phylum Arthropoda, in which the class Insecta was the one with the highest percentage (65.1%) and the lowest was Adenophorea the phylum Nematoda (0.3%). Dunnett's test showed that no significant differences in diversity (p = 0.5 and 0.4) and density (p = 0.8 and 0.4) between the plantations. Principal Component Analysis (PCA) indicated that only eucalyptus plantation showed a positive correlation between the density of macroinvertebrates and variables such as basal area and diameter at breastheight, and that in all three sites was positively correlated the diversity index of Hill with the contents of K, Ca, Mg, MO and N. We conclude that both plantations have similarly heterogeneity so resembling secondary forest, which was reflected in the diversity and density of soil macroinvertebrates.
Cittarium pica is an endangered Caribbean gastropod of ecological and economic importance. In order to provide the basis for the aquaculture development and/or population management of this species, the relationships among its body size and physiological variables associated with the energetic balance were assessed. Individual measurements of rates of egestion (ER), ingestion (IR), absorption (AR), oxygen consumption (OCR), ammonia excretion (UR), mucus production (MR), absorption efficiency (AE) and scope for growth (SFG), were carried out on specimens between 0.01 and 12.07 g of dry weight of the soft parts (DW) under controlled laboratory conditions. Most of the variables showed positive potential relationships with the DW of the animals (ER mg h -1 = 1.51 DW 0.37 , IR mg h -1 = 4.13 DW 0.32 , AR = 2.56 DW 0.30 , OCR mL O2 h -1 = 0.38 DW 0.74 , UR µg NH4 -N h -1 = 19.17 DW 0.78 , MR mg h -1 = 1.28 DW 0.14 and SFG = 36.92 DW 0.22 ). AE did not show any relationship with this variable. The large snails had faster input and output of energy compared to the small specimens, also having proportionally greater energetic expenditures, mucus production, and energetic balance.
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