Find research datasets worth reusing

Fig. 4 in Intestinal coccidiosis of anadromous and landlocked alewives, Alosa pseudoharengus, caused by Goussia ameliae n. sp. and G. alosii n. sp. (Apicomplexa: Eimeriidae)

Fig. 4. Goussia alosii from the intestine of landlocked alewives, bar = 10 μm. Wet mount of (A) highly elongated unsporulated oocysts and (B) sporulated oocysts with a thicker oocyst wall making up a very regular oval shape containing four highly elongated sporocysts. (C–E) Histology of coccidial stages in the intestine; (C) various stages of coccidia with an epicellular position within the intestinal epithelium; elongated unsporulated oocysts (arrows) found within the (D) intestinal epithelium and (E) within mucoid casts in the intestinal lumen.

Fig. 3 in Intestinal coccidiosis of anadromous and landlocked alewives, Alosa pseudoharengus, caused by Goussia ameliae n. sp. and G. alosii n. sp. (Apicomplexa: Eimeriidae)

Fig. 3. Goussia ameliae from landlocked alewives, bar = 10 μm. (A–C) Wet mounts of fresh coccidia preparations with (A) unsporulated oocysts and (B,C) sporulated oocysts containing four elongated sporocysts. (D–H) Histology documenting the development of the coccidian in the pyloric cecum, stained with H&E. (D) Meronts containing merozoites within the brush border on the surface of the intestinal epithelium; (E) early developmental stages (arrowheads) embedded within the brush border; (F) macrogamonts with an epicellular position on the intestinal epithelium; (G) microgametocytes (arrowhead) and unsporulated oocysts (arrow) which have sloughed from the epithelial surface; (H) severe coccidiosis with various developmental stages occupying most of the surface of the intestinal epithelium.

Fig. 2 in Intestinal coccidiosis of anadromous and landlocked alewives, Alosa pseudoharengus, caused by Goussia ameliae n. sp. and G. alosii n. sp. (Apicomplexa: Eimeriidae)

Fig. 2. Histology of coccidia infection in the intestine of anadromous alewives, stained with H&E, bar = 10 μm. (A,B) Spherical early developmental stages (arrowheads) within the brush border of the intestinal epithelium; (C) macrogamonts (arrowhead) (notice the notches nearly midway through the parasite, embedded within the surface of the intestinal epithelium); (D) macrogamonts with notches (arrowhead) and unsporulated elongated oocysts (arrows) within the intestinal epithelium.

Fig. 1 in Intestinal coccidiosis of anadromous and landlocked alewives, Alosa pseudoharengus, caused by Goussia ameliae n. sp. and G. alosii n. sp. (Apicomplexa: Eimeriidae)

Fig. 1. Goussia ameliae from anadromous alewives, bar = 10 μm. (A–C) Wet mounts of fresh coccidia preparations with (A) unsporulated oocysts, (B) oocysts in the process of sporulation, and (C) sporulated oocysts containing four sporocysts. (D–H) Histology documenting various stages of coccidia infection in the pyloric cecum, stained with H&E. (D) Intestinal epithelium with a severe infection of coccidia stages including gamonts and unsporulated oocysts covering the intestinal epithelium; (E) meront containing merozoites (arrow) attached to the microvillar surface of intestinal epithelial cells; (F) gamogony with macrogamonts (arrow) and microgametocytes (arrowhead) with an epicellular position; (G) unsporulated oocysts with an epicellular position (notice below, the focal necrosis to the intestinal epithelium); (H) a focal erosion in the intestinal epithelium with unsporulated and sporulated (arrow) oocysts released into the lumen.

Fig. 5 in Intestinal coccidiosis of anadromous and landlocked alewives, Alosa pseudoharengus, caused by Goussia ameliae n. sp. and G. alosii n. sp. (Apicomplexa: Eimeriidae)

Fig. 5. Line drawings of sporulated oocysts of Goussia ameliae from (A) anadromous and (B) landlocked alewives and (C) G. alosii sampled from landlocked alewives, bar = 5 μm.

Fig. 6 in Intestinal coccidiosis of anadromous and landlocked alewives, Alosa pseudoharengus, caused by Goussia ameliae n. sp. and G. alosii n. sp. (Apicomplexa: Eimeriidae)

Fig. 6. Phylogenetic tree based on maximum likelihood analysis (-ln = 5197.3909) based on 16 sequences obtained from Genbank and one sequence from this study (G. ameliae denoted with a bold circle). Goussia ameliae fit into a fish Goussia clade, which is distinct from other fish coccidians (*). Theilleria parva was used as an outgroup to root the tree.

opencc-zeroAug 2020View details →

Data from: A century of intermittent eco-evolutionary feedbacks resulted in novel trait combinations in invasive great lakes Alewives (Alosa pseudoharengus)

<p>Species introductions provide opportunities to quantify rates and patterns of evolutionary change in response to novel environments. Alewives (<em>Alosa pseudoharengus</em>) are native to the East Coast of North America where they ascend coastal rivers to spawn in lakes, and then return to the ocean. Some populations have become landlocked within the last 350 years and diverged phenotypically from their ancestral marine population. More recently alewives were introduced to the Laurentian Great Lakes (~150 years ago), but these populations have not been compared to East Coast anadromous and landlocked populations. We quantified 95 years of evolution in foraging traits and overall body shape of Great Lakes alewives and compared patterns of phenotypic evolution of Great Lakes alewives to East Coast anadromous and landlocked populations. Our results suggest that gill raker spacing in Great Lakes alewives has evolved in a dynamic pattern that is consistent with responses to strong but intermittent eco-evolutionary feedbacks with zooplankton size. Following their initial colonization of Lakes Ontario and Michigan, dense alewife populations likely depleted large-bodied zooplankton, which drove a decrease in alewife gill raker spacing. However, the introduction of large, non-native zooplankton to the Great Lakes in later decades resulted in an increase in gill raker spacing, and present-day Great Lakes alewives have gill raker spacing patterns that are similar to the ancestral East Coast anadromous population. Conversely, contemporary Great Lakes alewife populations possess a gape width consistent with East Coast landlocked populations. Body shape showed remarkable parallel evolution with East Coast landlocked populations, likely due to a shared response to the loss of long-distance movement or migrations. Our results suggest the colonization of a new environment and cessation of migration can result in rapid parallel evolution in some traits, but contingency also plays a role, and a dynamic ecosystem can also yield novel trait combinations.</p>

opencc-zeroJan 2013View details →

Data from: Consumer interaction strength may limit the diversifying effect of intraspecific competition: a test in alewife (Alosa pseudoharengus).

Intraspecific competition is considered a principal driver of dietary variation, however, empirical studies provide mixed support for this mechanism. Here we link comparative and experimental work testing the effects of competition and resource availability on the dietary variation of alewife (Alosa pseudoharengus). Alewife, a consumer with extreme effects on its resources, are specifically utilized to additionally test the idea that that the strength of the interaction between a consumer and its resources may diminish the diversifying effect of competition. First, we compared the short- and long-term diet measures of from wild populations across a range of densities. Second, in a series of large-scale field mesocosm experiments we explored the influence of competition and interaction strength on alewife dietary variation. Results from the whole lake comparison and field experiments indicated that increasing competition was negatively correlated with population dietary variation. Further, altering the strength of the interaction between alewife and their prey via prey supplementation eliminated this negative relationship. Collectively, our results suggest that competitive interactions may not drive dietary diversification in highly effective consumers. Our results also suggest that further consideration of the strength of species interactions (and the consumer traits that underlie them) would improve our understanding of the link between intraspecific competition and variation

opencc-zeroDec 2017View details →

Data from: Evaluating the potential for pre-zygotic isolation and hybridization between landlocked and anadromous alewife (Alosa pseudoharengus) following secondary contact

The recent increase of 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 pre-zygotic 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% to 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 was 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 pre-zygotic isolating mechanisms are minimal, leading to potentially rapid ecological and evolutionary changes in restored habitats.

publicApr 2018View details →

Data from: Evaluating the potential for pre-zygotic isolation and hybridization between landlocked and anadromous alewife (Alosa pseudoharengus) following secondary contact

Open the record for dataset details and reuse information.

publicAug 2020View details →

Data from: A century of intermittent eco-evolutionary feedbacks resulted in novel trait combinations in invasive great lakes Alewives (Alosa pseudoharengus)

Open the record for dataset details and reuse information.