Reproductive seasonality and nest-site differentiation in three closely related armoured catfishes (Siluriformes: Callichthyidae)

Abstract

SynopsisThree sympatric, closely related armoured catfishes showed a similar, bimodal breeding season in coastal plain swamps in Suriname (South America). The bimodal pattern of reproduction in Callichthys callichthys, Hoplosternum littorale and Hoplosternum thoracatum was correlated to the annual distribution of rainfall. Floating bubble nests were constructed throughout the period of swamp inundation (rainy season). Close inspection of the timing of reproduction of H. littorale in northern South America revealed the relationship between reproduction and rainfall, but also unexpected differences in the length of the breeding season. Strong interspecific competition among the three species was probably avoided through differentiation of nest sites with respect to water depth, distance to the nearest tree, distance to the edge of the swamp, and cover above the nest. Nests of H. littorale were built in herbaceous swamps, while C. callichthys and H. thoracatum build their nests in swamp-forest. Nests of C. callichthys were observed in extremely shallow water or in holes. Few nests of the three species were observed in canals. Over large parts of their geographical range C. callichthys and H. thoracatum are found in small rainforest streams. Several aspects of the reproductive ecology and behaviour of both species are probably related to the unpredictability of the stream habitat.

Effects of wave action on nesting activity in the littoral five-spotted wrasse, <i>Symphodus roissali</i>, (Labridae), in the northwestern Mediterranean Sea

“…This relatively large percentage of abandoned nests can reflect the high percentage of nests that did not acquire eggs, and which were subsequently left by the male one or two days after the begining of construction, as observed previously in freshwater fishes (Mol, 1996).…”

“…Several studies have attempted to relate environmental parameters, mostly rainfall and its effects on current velocity and flooding, and the nesting activities of freshwater fishes (Noltie and Keenleyside, 1987;Jennings and Philipp, 1994;Lucas and Orth, 1995;Mol, 1996). However, there are a few studies that relate wave action with nesting success in lakes (Goff 1985(Goff , 1986Nack et al, 1993;Popiel et al, 1996), and no studies on the direct effects of wave action on nest viability in marine nesting fishes.…”

Loss of biodiversity in a conservation unit of the Brazilian Atlantic Forest: the effect of introducing non-native fish species

“…The fact that fish cultivation is one of the main sources of dispersion of non-native species is well known (Casal, 2006;Pelicice et al, 2013). In the middle Rio Doce region it was responsible for the appearance of C. gariepinus and tilapias, among other species .…”

“…The ecological alterations in the fish community due to its population expansion is not known yet, since it is not a predator species but can compete for common resources with other species such as spawning areas. This species is well adapted to the environment presenting biological adaptations such as obligated air breather, parental care and floating foam nest building and guarding by males (Reis, 2003;Mol, 1996;Reis, 1998). Considering that diet studies performed at the wetlands of the upper Paraná River basin, its native area, indicate high predation of microcrustaceans, chironomids and nematodes (Hahn et al, 1997), it is possible that its higher impact is on zooplankton and zoobenthos communities, disrupting the food web and consequently the ecosystem functioning.…”

“…However, as other countries of the world it has suffered with negligent introduction of non-native species, mainly for agriculture and livestock production. Particularly in continental waters the introductions aiming at sport fishing, biological control and aquiculture are of paramount importance (Agostinho et al, 1994;Vitule et al, 2009;Pelicice et al, 2013). Although introductions are not new, only after 1990 studies aiming at non-native species became frequent (Speziale et al, 2012) and therefore, there are still many gaps about their impacts on the environment (Britton and Orsi, 2012;Vitule and Prodocimo, 2012).…”