Dataset Information

Evaluating the potential for prezygotic isolation and hybridization between landlocked and anadromous alewife (Alosa pseudoharengus) following secondary contact.

ABSTRACT: The recent increase in river restoration projects is altering habitat connectivity for many aquatic species, increasing the chance that previously isolated populations will come into secondary contact. Anadromous and landlocked alewife (Alosa pseudoharengus) are currently undergoing secondary contact as a result of a fishway installation at Rogers Lake in Old Lyme, Connecticut. To determine the degree of prezygotic isolation and potential for hybridization between alewife life history forms, we constructed spawning time distributions for two anadromous and three landlocked alewife populations using otolith-derived age estimates. In addition, we analyzed long-term data from anadromous alewife migratory spawning runs to look for trends in arrival date and spawning time. Our results indicated that anadromous alewife spawned earlier and over a shorter duration than landlocked alewife, but 3%-13% of landlocked alewife spawning overlapped with the anadromous alewife spawning period. The degree of spawning time overlap was primarily driven by annual and population-level variation in the timing of spawning by landlocked alewife, whereas the timing and duration of spawning for anadromous alewife were found to be relatively invariant among years in our study system. For alewife and many other anadromous fish species, the increase in fish passage river restoration projects in the coming decades will re-establish habitat connectivity and may bring isolated populations into contact. Hybridization between life history forms may occur when prezygotic isolating mechanisms are minimal, leading to potentially rapid ecological and evolutionary changes in restored habitats.

SUBMITTER: Littrell KA

PROVIDER: S-EPMC6183454 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Evaluating the potential for prezygotic isolation and hybridization between landlocked and anadromous alewife (<i>Alosa pseudoharengus</i>) following secondary contact.

Littrell Katherine A KA Ellis David D Gephard Stephen R SR MacDonald Andrew D AD Palkovacs Eric P EP Scranton Katherine K Post David M DM

Evolutionary applications 20180614 9

The recent increase in river restoration projects is altering habitat connectivity for many aquatic species, increasing the chance that previously isolated populations will come into secondary contact. Anadromous and landlocked alewife (<i>Alosa pseudoharengus</i>) are currently undergoing secondary contact as a result of a fishway installation at Rogers Lake in Old Lyme, Connecticut. To determine the degree of prezygotic isolation and potential for hybridization between alewife life history for ...[more]

PMID: 30344627

Similar Datasets

Project description:Anadromous alewives, Alosa pseudoharengus, have experienced significant population level declines caused by factors including habitat destruction. Alewives occur in two different life histories, anadromous and landlocked forms. The landlocked alewife evolved from ancestral anadromous populations, resulting in an exclusively freshwater and phenotypically unique form. The occurrence of parasites in a host is linked to the environment, making alewives an ideal model to compare parasitology within a single species with contrasting life histories. Currently, little information exists on the presence and impacts of parasites in these fish populations; the present study sets out to better understand coccidiosis in the threatened anadromous populations and to understand how coccidian parasites compare in both life history forms. The intestinal coccidian, Goussia ameliae n. sp., was described infecting the pyloric cecum of 76% and 86% of young-of-the-year and adult anadromous alewives, respectively, from the Maurice River, New Jersey, USA. The coccidian was found in landlocked alewife populations with a prevalence of 92% and 34% in YOY and adult fish, respectively. An analysis of the small subunit 18S ribosomal RNA gene of G. ameliae from both life history forms demonstrated that the coccidian had 100% sequence identity, confirming the same parasite species in both forms. Though genetic analysis demonstrated G. ameliae to be identical, some differences were observed in sporulation and morphology of the parasite within the two populations. The sporocysts in anadromous populations were shorter and wider, and sporulation timing differed from that of landlocked fish. These differences may either be attributed to differences in the host type or to the sporulation environment. Lastly, alewives from landlocked populations were frequently co-infected with a second coccidian species in the posterior intestine, which occurred at a lower prevalence. This species, G. alosii n. sp., was described based on morphological characters of the sporulated oocysts in fresh parasitological preparations.

Dataset Information

Evaluating the potential for prezygotic isolation and hybridization between landlocked and anadromous alewife (Alosa pseudoharengus) following secondary contact.

Publications

Evaluating the potential for prezygotic isolation and hybridization between landlocked and anadromous alewife (<i>Alosa pseudoharengus</i>) following secondary contact.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets