Life-stage-dependent sensitivity of the cyclopoid copepod Mesocyclops leuckarti to triphenyltin

In recent times aquaculture has become an increasingly important part of the world economy. Copepods play major roles in pond ecosystems serving as food for small fish, micro-predators on fish and other organisms, fish parasites, intermediate hosts of fish parasites and hosts and vectors of human diseases like cholera. Growth, reproduction and biochemical composition were analyzed for the copepod Mesocyclops leuckarti fed on four diets and their ratio like Bakers yeast (B), Baker’s yeast+ Wheat flour (BW, 1:2), Bakers yeast + Chicken manure (BC, 1:2) and Bakers yeast + Chicken manure + Wheat flour (BCW, 1:2:2). The mean peak density of the copepod population was 569 individual/lit, for all four diets used. The highest was 587 individual/lit, on diet having combination of Bakers yeast, Chicken manure and Wheat flour (BCW). A small copepod Mesocyclops leuckarti tends to have a short life span and it was found to be important food items for fish larvae.

Download Full-text

Molecular characterization and phylogenetic analysis of cyclopoid copepod Mesocyclops leuckarti using mtCOI

International Journal of Bioassays ◽

10.21746/ijbio.2017.04.008 ◽

2017 ◽

Vol 6 (04) ◽

pp. 5365

Author(s):

Gomathi Jeyam ◽

Ramanibai R*

Keyword(s):

Phylogenetic Analysis ◽

Dna Barcode ◽

Coi Gene ◽

Universal Primers ◽

Cyclopoid Copepod ◽

Mitochondrial Coi ◽

Mitochondrial Coi Gene ◽

Mesocyclops Leuckarti ◽

Coi Sequences ◽

The Individual

Copepods are the most abundant metazoan zooplankton amongst multicellular animals. The present study was performed to establish the sequence variation of partial mitochondrial Cytochrome c Oxidase I gene (COI) from Mesocyclops leuckarti collected from the Retteri Lake, Chennai in order to identify and describe their genetic divergence along with the phylogenetic relatedness with other species. DNA of individual M. leuckarti was extracted and the partial mitochondrial COI gene was successfully amplified using the universal primers LCO-1490 and HCO-2198. A 576bp partial mitochondrial COI gene sequence was obtained. Analysis of partial COI sequences of M. leuckarti exposed 93% similarity amongst all the individual of copepods selected from Genbank. The obtained COI sequences of Cyclopoid copepod was confirmed with BLAST analysis. Phylogenetic analysis of M. leuckarti along with selected out groups from different taxa level further supports the clarity and maintained the authentic of taxonomy up to the subclass level: Copepoda. The results showed that, the COI barcoding of cyclopoid copepod species could be distinguished from the others very clearly. Thus, it strongly indicated that COI may be a useful construction of a comprehensive DNA barcode database for copepods inhabiting the freshwater bodies in Chennai.

Download Full-text

Fear of Contamination Goal and Life-stage Specific Biases

PsycEXTRA Dataset ◽

10.1037/e722352011-066 ◽

2008 ◽

Author(s):

Julie Y. Huang ◽

J. A. Bargh

Keyword(s):

Life Stage

Download Full-text

A Life Stage Model of Climate Change Related Perceptions and Attitudes

PsycEXTRA Dataset ◽

10.1037/e722352011-111 ◽

2008 ◽

Author(s):

Emma Soane ◽

Rebecca Lunn

Keyword(s):

Climate Change ◽

Life Stage ◽

Stage Model ◽

Perceptions And Attitudes

Download Full-text

Habitat fragmentation causes collapse of kelp recruitment

Marine Ecology Progress Series ◽

10.3354/meps13422 ◽

2020 ◽

Vol 648 ◽

pp. 111-123

Author(s):

C Layton ◽

MJ Cameron ◽

M Tatsumi ◽

V Shelamoff ◽

JT Wright ◽

...

Keyword(s):

Habitat Fragmentation ◽

Patch Size ◽

Life Stage ◽

Extended Period ◽

Anthropogenic Disturbances ◽

Anthropogenic Sources ◽

Kelp Forests ◽

Natural Disturbances ◽

Short Term ◽

Turf Algae

Kelp forests in many regions are experiencing disturbance from anthropogenic sources such as ocean warming, pollution, and overgrazing. Unlike natural disturbances such as storms, anthropogenic disturbances often manifest as press perturbations that cause persistent alterations to the environment. One consequence is that some kelp forests are becoming increasingly sparse and fragmented. We manipulated patch size of the kelp Ecklonia radiata over 24 mo to simulate persistent habitat fragmentation and assessed how this influenced the demography of macro- and microscopic juvenile kelp within the patches. At the beginning of the experiment, patch formation resulted in short-term increases in E. radiata recruitment in patches <1 m2. However, recruitment collapsed in those same patches over the extended period, with no recruits observed after 15 mo. Experimental transplants of microscopic and macroscopic juvenile sporophytes into the patches failed to identify the life stage impacted by the reductions in patch size, indicating that the effects may be subtle and require extended periods to manifest, and/or that another life stage is responsible. Abiotic measurements within the patches indicated that kelp were less able to engineer the sub-canopy environment in smaller patches. In particular, reduced shading of the sub-canopy in smaller patches was associated with proliferation of sediments and turf algae, which potentially contributed to the collapse of recruitment. We demonstrate the consequences of short- and longer-term degradation of E. radiata habitats and conclude that habitat fragmentation can lead to severe disruptions to kelp demography.

Download Full-text