•Fisheries conservation in Honduras is challenged by lack of data.•Ecomorphology provides insights for species conservation and management.•Honduran fish stocks are differentiated by local ...environmental conditions.•River discharge drives fish body shape differentiation through phenotypic plasticity.
Many Caribbean nations lack information on the ecology and biology of marine species, which are essential for food security and livelihoods in the region. This study aimed to advance the knowledge of two commercially important fish species, lane snapper (Lutjanus synagris) and white grunt (Haemulon plumierii), using cost-efficient techniques. Specifically, geometric morphometrics was used to assess the presence of ecomorphological groups (characterized by body shape variation associated with local environmental variables) in the Honduran Caribbean continental platform. Photographs of 104 lane snapper and 99 white grunt adult individuals were taken and digitalized with 12 landmarks. Subsequently body shape patterns were related to environmental variables using Distance-based linear models and Partial Least Squares. Results enabled the identification of ecomorphological groups or fish stocks in the study region associated with the environmental conditions of each site. Distance to river mouth and Chlorophyll a, both indicators of land-based stressors, appeared as the primary driving force of body shape differentiation in the species. These results are key for the development of informed reef fisheries management policies in the Caribbean region.
The complex life cycles of most trematode parasites include three hosts. The first intermediate host is a snail, the second is normally a teleost fish and a piscivorous bird serves as the definitive ...host. Lymnaeid snails are most likely to be responsible for cercarial shedding, which infect exposed fish and in turn are eaten by piscivorous birds. From 2008 to 2010 fish in the Okavango and Orange-Vaal River Systems were collected and dissected in order to determine the prevalence and intensity of larval trematode infections in the eyes and brains. This paper discusses the possible ecological factors which can influence the probability of certain fish species becoming infected with diplostomid cercariae and hence metacercariae. The feeding strategies and sizes of piscivorous birds, which could act as definitive hosts for the adult worms, are summarized and discussed. Information on the snail species responsible for furcocercous cercarial shedding in the two study sites is also included.
Earthworms play an important role in soil quality, including forest soils. Their presence in zooedafon, as well as their abundance and species diversity, also indicate the state of the soil profile. ...The species diversity of the representatives of this group of macrofauna in a beech forest in the Bieszczady Mountains are recounted in this article. Earthworms were investigated in the soil of four sites selected near Ustrzyki Górne in Carpathian beech woods Dentario glandulosae - Fagetum (sites in D. g. Fagetum festucetosum, - typicum, - lunarietosum and - allietosum), every month during the annual cycle during two periods: a/ in 1986-1987 and b/ in 2009-2010. It was done according to the Zicsi’s recommendations, using the Zajonc combinated method. In the 80. thirteen earthworm species were found (total of 1 805 specimens) in the soil of four sites investigated. In decreasing order of numbers there were: Dendrobaena alpina alpina (Rosa 1984), Allolobophora cernosvitoviana (Zicsi 1967), Aporectodea rosea rosea (Sav.,1826), Aporectodea caliginosa (Sav., 1826), Lumbricus terrestris L., 1758, Octolasium lacteum (Orley,1881), Allolobophora carpathica (Cog., 1927), Fitzingeria platyura montana (Cer., 1932), Octodrilus transpadanus (Rosa, 1884), Dendrobaena octaedra (Sav., 1826), Eisenia lucens (Waga, 1857), Lumbricus rubellus (Hoffm., 1843), Dendrodrilus rubidus tenuis (Eisen, 1874). Twenty years later, in the years 2009-2010, eleven earthworm species were found in the soil of the same four sites investigated (total of 660 specimens). There was no occurrence of L. rubellus, and O. transpadanus. For all cited species, vertical distribution dynamics in an annual cycle was investigated as well as the preferred soil layer in terms of soil profile. The features of the delineated earthworm species and the soil levels they prefer allowed their affiliation with the ecological groups defined by Bouche to be considered or determined. Knowledge about the association of earthworms to ecomorphological groups in natural or a little changed ecosystem is becoming very useful, for example at the time of the reclamation of degraded soils with Lumbricidae as bioindicators.
The complex life cycles of most trematode parasites include three hosts. The first intermediate host is a snail, the second is normally a teleost fish and a piscivorous bird serves as the definitive ...host. Lymnaeid snails are most likely to be responsible for cercarial shedding, which infect exposed fish and in turn are eaten by piscivorous birds. From 2008 to 2010 fish in the Okavango and Orange-Vaal River Systems were collected and dissected in order to determine the prevalence and intensity of larval trematode infections in the eyes and brains. This paper discusses the possible ecological factors which can influence the probability of certain fish species becoming infected with diplostomid cercariae and hence metacercariae. The feeding strategies and sizes of piscivorous birds, which could act as definitive hosts for the adult worms, are summarized and discussed. Information on the snail species responsible for furcocercous cercarial shedding in the two study sites is also included.
PDF