Fish as vectors in the dispersal of Bythotrephes cederstroemi: diapausing eggs survive passage through the gut

ABSTRACT The family Rivulidae is the fourth most diverse clade of Neotropical fishes. Together with some genera of the related African family Nothobranchiidae, many rivulids exhibit a characteristic annual life cycle, with diapausing eggs and delayed embryonic development, which allows them to survive in the challenging seasonal ponds that they inhabit. Rivulidae also includes two species known as the only the self-fertilizing vertebrates and some species with internal fertilization. The first goal of this article is to review the systematics of the family considering phylogenetic relationships and synapomorphies of subfamilial clades, thus unifying information that is dispersed throughout the literature. From this revision, it is clear that phylogenetic relationships within Rivulidae are poorly resolved, especially in one of the large clades that compose it, the subfamily Rivulinae, where conflicting hypotheses of relationships of non-annual and annual genera are evident. The second goal of this work is to present an updated phylogenetic hypothesis (based on mitochondrial, nuclear, and morphological information) for one of the most speciose genus of Rivulidae, Austrolebias. Our results confirm the monophyly of the genus and of some subgeneric clades already diagnosed, but propose new relationships among them and their species composition, particularly in the subgenus Acrolebias.

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Recovery of Hesperodiaptomus arcticus populations from diapausing eggs following elimination by stocked salmonids

Canadian Journal of Zoology ◽

10.1139/z96-144 ◽

1996 ◽

Vol 74 (7) ◽

pp. 1292-1297 ◽

Cited By ~ 33

Author(s):

Brian R. Parker ◽

Frank M. Wilhelm ◽

David W. Schindler

Keyword(s):

Lake Sediments ◽

Calanoid Copepod ◽

Negative Impact ◽

Experimental Studies ◽

Fish Population ◽

Alpine Lakes ◽

Fish Stocking ◽

Egg Bank ◽

Diapausing Eggs ◽

Gammarus Lacustris

Hesperodiaptomus arcticus, a predatory calanoid copepod, was eliminated from two alpine lakes within 6 years of stocking with salmonids. Using historical and contemporary Zooplankton and fish data, sediment analysis for diapausing eggs, and experiments on predation of Gammarus lacustris on diapausing eggs of H. arcticus, we assess the fate of these populations 35 years after fish stocking. In Pipit Lake, in which the trout introduction failed within 21 years, we propose that H. arcticus recovered as a result of hatching of diapausing eggs held in the sediments. In Snowflake Lake the diapausing egg bank was exhausted prior to the loss of the fish population 25 years after first stocking and H. arcticus recovery did not occur. Experimental studies indicate that G. lacustris predation on diapausing eggs probably occurs within the sediments. Combined with a 10-fold difference in G. lacustris density between Snowflake and Pipit lakes the results of the predation experiments imply that G. lacustris had a strong negative impact on the abundance of diapausing eggs held in Snowflake Lake sediments and therefore reduced the ability of the population to recover following perturbation.

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Hatching and viability of rotifer diapausing eggs collected from pond sediments

Freshwater Biology ◽

10.1111/j.1365-2427.2006.01583.x ◽

2006 ◽

Vol 51 (7) ◽

pp. 1351-1358 ◽

Cited By ~ 29

Author(s):

EDUARDO M. GARCIA-ROGER ◽

MARIA JOSE CARMONA ◽

MANUEL SERRA

Keyword(s):

Diapausing Eggs ◽

Pond Sediments

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Dormant plasticity of rotifer diapausing eggs in response to predator kairomones

Biology Letters ◽

10.1098/rsbl.2021.0422 ◽

2021 ◽

Vol 17 (11) ◽

Author(s):

Xuwang Yin ◽

Yuecen Zhao ◽

Shuang Tian ◽

Xiaochun Li

Keyword(s):

Life Cycles ◽

Freshwater Ecosystems ◽

Sexual Life ◽

Hatching Rate ◽

Ecological Implication ◽

Maternal Environment ◽

Predator Prey ◽

Diapausing Eggs ◽

Embryonic Exposure ◽

Phenotypic Responses

In freshwater ecosystems, hatching strategy of diapausing eggs (DEs) under predation risk has important ecological implication for zooplankters. Although kairomones released by predators can induce phenotypic responses of prey, hatching patterns of DEs in response to kairomones have received contradictory conclusions in zooplankters. Maternal environment may also affect hatching strategy of DEs during predator–prey interactions. We used classical Brachionus calyciflorus – Asplanchna models to determine the timing and proportion of DE hatching in association with parental and embryonic exposure to kairomones. Results obtained from two Brachionus clones supported the hypothesis that DEs could detect Asplanchna kairomones and adjust hatching patterns. DEs showed early and synchronous hatching patterns in the environment with kairomones. Data also supported the prediction that DEs could gain information about predators from maternal environments and adjusted their hatching pattern in response to the presence of kairomones. Compared with DEs from Brachionus mothers not exposed to kairomones, DEs produced by mothers that were experienced with kairomones attained a higher hatching rate when both of them hatched in the environment either with or without kairomones. Our results suggest that DEs of B . calyciflorus possess dormant plasticity to defend against predation from Asplanchna , which may be regulated by maternal environmental effects during sexual life cycles.

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