Parampheres Roewer, 1913 is a relatively common genus of South American harvestmen. This genus is easily diagnosed by the remarkable yellow patches on the prosoma. Nonetheless, species determination within this group is challenging due the convoluted taxonomic history of the group and lack of a recent revision. In this study we revise Parampheres and describe a new species, Parampheres tenebris sp. nov., from Parque Nacional da Serra Geral, Rio Grande do Sul, Brazil. The new species can be distinguished from the other species of the genus by having dorsal scutum dark, and apophysis of coxa IV of male elongated. Furthermore, we propose the following new synonymies: Callampheres boliviensis Roewer, 1913, Pertyana ronae Mello-Leitão, 1927 and Parampheres tibialis Roewer, 1917 with Parampheres pectinatus Roewer, 1913. Parampheres now includes four species distributed from southern Brazil to adjacent areas in Argentina and Uruguay. In addition, we present a phylogenetic hypothesis based on morphological characters that supports the transfer of Parampheres from Gonyleptinae to Caelopyginae.

This work presents the effects of an anatoxin-a(s)-containing extract on a cockroach semi-isolated heart preparation and the results supporting the extract’s biological activity on acetylcholinesterase (purified from ell). The presence of the toxin in cyanobacterial strains Anabaena spiroides (ITEP-024, ITEP-025 and ITEP-026) isolated from the Tapacurá reservoir in Pernambuco, Brazil, was confirmed by means of liquid chromatography coupled to an ion-trap mass spectrometer. The anticholinesterase activity was assessed biochemically by the Ellman test and was confirmed by measuring the cockroach’s heart rate. The concentration of the extract containing the tested anatoxin-a(s) (antx-a(s)) (10, 16 and 100 μg.μL-1) inhibited the eel acetylcholinesterase (AChE) by more than 90%. The cockroach cardiac frequency increased by a maximum of about 20% within 29 min after the addition of 2.5x10³ μg of extract containing antxa (s).g-1 bw (n=9, p<0.05). Our results strongly indicate that antx-a(s) is capable of exerting biological effects on cockroach, indicating that more research might be conducted to determine its role in the environment, especially on insects.