Abundance and Diversity of Snails in Relation to Physicochemical Parameters along Kwadom Stream, Gombe State, Nigeria

Aims: The aim of the study is to investigate the abundance and diversity of snails along Kwadom stream, Gombe state, Nigeria. Study Design: Snails were collected using a benthic scoop net with mesh size of 0.2 mm and hand picking from three sampling stations (home, farmlands, and fishponds sites) along Kwadom stream; between 6:30 am to 11:00 am weekly. In addition, physicochemical parameters (temperature, dissolved oxygen, conductivity, alkalinity, water depth and pH) were measured fortnightly to determine their effect on the diversity of snail species. Place and Duration of Study: The study was conducted along Kwadom stream in Yamaltu Deba Local Government Area of Gombe State, Nigeria from March to July 2021. Methodology: Snails were collected from each of the three stations and identified to species level using hand lens and taxonomy keys. Water physicochemical parameters: temperature, dissolved oxygen, conductivity, alkalinity, water depth and pH were measured using standard method. General linear models (GLM) were used to compare the abundance and diversity of the snails across the sampling station, as well as the effect of physicochemical parameters on the diversity of snails. Results: 160 individual snails were recorded from 11 species, including Biomphalaria pfeifferi– the intermediate host of Schistosoma mansoni. The result showed there was a significant difference in the abundance of snails (p<0.01) across the three study sites – home site 68 (42.5%), farmlands site 56 (35%) and fishpond site 36 (22.5%). The home site had a higher diversity of snail species (p<0.01) relative to the farmlands and fishponds sites. Temperature, conductivity, and alkalinity had a significant effect on the diversity of snails. Conclusion: Overall, Kwadom stream harbors many individual snail species, suggesting the need for educating the public on the mode of transmission of diseases that are caused by these snails.

Review Article: Homelandings: Postcolonial Diasporas and Transatlantic Belongings (2016) by Rahul Gairola

We all discover over and over again the kind of strange and violent stranglehold history has over us. We deploy histories to explain our pasts, identify the present, and orient us to the future. As Rahul K. Gairola shows in Homelandings: Postcolonial Diasporas and Transatlantic Belongings, the multiple currents of history have dictated our methods for establishing our home-sites: who belongs and who does not belong in any given place. Our “at-home” practices, one dimension of “the double-bind of history as home…” (2016, xvi), have a deep and lasting impact on how we move about and participate in the world-at-large. Homelandings provides a timely intervention into the theoretical discourse on the “home-site” as the outcome of a “home-economics” that continually reenacts the persistent racism, classicism, sexism, and queerphobia of a neoliberal bio-political governmentality of the Anglosphere (Bennet’s term, cited in Gairola, 18). The project offers “homelandings,” Gairola’s neologism, as the process of resistance to and reappropriation of “home-sites”: “producing new homes in which alternative modes of community and belonging flourish and reproduce” (17). Homelandings—with “landings” as the demarcator of that which is in motion, always about to happen—then act as a series of transversal disruptors of the neoliberal sphere.

Limited effects of source population identity and number on seagrass transplant performance

Global declines in coastal foundation species highlight the importance of effective restoration. In this study, we examined the effects of source population identity and diversity (one vs. three sources per plot) on seagrass (Zostera marina) transplant success. The field experiment was replicated at two locations in Massachusetts with adjacent naturalZostera marinabeds to test for local adaptation and source diversity effects on shoot density. We also collected morphological and genetic data to characterize variation within and among source populations, and evaluate whether they were related to performance. Transplants grew and expanded until six months post-transplantation, but then steadily declined at both sites. Prior to declines, we observed variation in performance among source populations at one site that was related to morphological traits: the populations with the longest leaves had the highest shoot densities, whereas the population with the shortest leaves performed the worst at six months post-transplantation. In addition, multiple source plots at this same transplant site consistently had similar or higher shoot densities than single source plots, and shoots from weak-performing populations showed improved performance in multiple source plots. We found no evidence for home site advantage or benefits of population-level genetic variation in early transplant performance at either site. Our results show limited effects of source population on early transplant performance and suggest that factors (e.g., morphology) other than home site advantage and population genetic variation serve a role. Based on our overall findings that transplant success varied among source populations and that population diversity at the plot level had positive but limited effects on individual and plot performance, we support planting shoots from multiple source sites in combination to enhance transplant success, particularly in the absence of detailed information on individual source characteristics.