This study was conducted to analyse the use of coconut water doses achieve a higher percentage males in guppy breeding and how it affects survival fry. The search took place Mertoyudan, Magelang district between November 2021 January 2022. research plan completely randomized design with 4 treatments replicates. Treatments this were immersed gravid females at 0%; 50%; 55%; 60% solution concentra...

Compared to egg-laying fish, live-bearing species invest much energy in the production of fewer, yet relatively more developed offspring. Although in many live-bearing species (e.g. mammals) viviparity is combined with extensive brood care after birth, this is not the case in the Poeciliidae, a family of freshwater fish that includes the well-known guppy (Poecilia reticulata), mollies (subgenus...

The authors examined the relationships between 2 "personality" dimensions (Approach and Fear Avoidance) and 2-way active avoidance learning performance in the guppy (Poecilia reticulata). Contrary to expectations (based on prior rodent studies), higher fearfulness facilitated both earlier appearance and acquisition of the shuttlebox avoidance responses, especially in the less exploratory and ac...

Differences in the exploratory behavior and social tendencies of 29 guppies (Poecilia reticulata) in 2 domains of situations involving novelty and conspecincs were investigated. Consistent individual differences were found in most behavior patterns. Two behavioral dimensions (Activity Exploration and Fear Avoidance) were identified in the novelty situations. Likewise, 2 dimensions (Sociability ...

Mozambique tilapia Oreochromis mossambicus were recently discovered in ‘Aimakapā Fishpond, a 12-hectare brackish-water wetland complex in Kaloko-Honokōhau National Historical Park, on the Island of Hawai’i. As a possible eradication method, we evaluated rotenone, a natural piscicide used in fish management and the active ingredient in plants traditionally used by indigenous Hawaiians for captur...

Evolutionary history, parental experience and individual provide distinct avenues by which the environment alters phenotypes, yet mechanisms mediating phenotypic variation on these timescales may interact. Here we examine how juvenile jointly modify offspring phenotypes in Trinidadian guppy, Poecilia reticulata. Parents were reared laboratory either with or without predator cues, split cues. We...