A new species of Bosminopsis (Crustacea, Cladocera) from the Rio Negro ()

Abstract

It is described a new species Bosminopsis negrensis from the lower Rio Negro. INTRODUCTIONOnly a single species of 8osminopsis, 8. deitersi, is known. According to Hutchinson ( 1967) it oi tends to be warm temperate to tropical··. In South America it was originally described by RICHARD (1895) from the Rio de La Plata, Argentina. Later it was also found in Mato Grosso, Brazil by DADAY (1903) and in the delta of the Amazon river (Stingel in, 1904), As the sampling of the author shows, 8. deitersi is a common plankter in the black waters of the Amazon basin. In the same type of water was tound Bosminopsis negrensis. DESCRIPTIONGenerally seen 8. negrensis is very sim i lar to the long known 8. deitersi. The striking difference is the long posterior spine of B. negrensis whtch reminds of some Daphnia.THE FEMALE HEAD ( Fig. 1, 1; Fig. 5).The head is indented above the eye (the socalled supra-ocular depression). There is a prolonged rostrum on which inserts the first antenna. The rostrum and te antennules are curved caudad, the tip of the antennule points downward. Rostrum and antennules are studded with short spinules, which on the rostrum stand in a row whereas on the antennules are Gerd-Oitmann Brandorff (""") irregular. At the end of the first antenna there are long, straggling, olfactory setae like in B. deitersi. The surface of the head is reticulated. The labrum is big, the lower part bears fine hairs .The second antenna consists of a large basipod. an endopod of three segments and an exopod of three segments. The basipod has one sensory seta that originates near the base ot the segment. The first two segments of the second antennal endopod each bear one long swimming seta while the third segment has three. The exopod has only three swimming setae on the distai segment. THE BODY SHELLThe body shell is rounded trapezoidal with the greater width cranial and the smaller caudal. On the ventro-caudal margin of the shell are two setae of about 50JA-m length and a short spinule. In the dorso-posterior corner ot the shell originates a long spine which is studded with short spinules. Only the first fifth of the posterior spine lacks these spinules. The length ot the spine is about 3/4 of the length of the animal. POSTABDOMEN (Fig. 2) The postabdomen is elongated and ends with the distai claws. There are one or two rows of four spinules and two rows of short hairs. On the basis of the claws is a large spine .r·l-Max-Pianck·lnst. of Limnology, Dep . Tropical Ecology, 23Piõn, Germany. 110-Brandorff MALE ( Fig. 3; Fig. 6)There are no great differences between the morphology of the male and the female . Evident is the dorsal depression of the shell of the male. Quite different are also the antennules and the first thoracic limb. The very long pair of antennules oríginate trom the anterior end of the ventral margin of the head. The distai end of each antennule bears many short spinules. Near the head on the antennule is a sensory seta and a row of short hairs that follows the longitudinal extension of• the antenn...

Zooplankton composition of ten reservoirs in southern Brazil

“…The higher numbers of species of Bosminidae here are due chiefly to the addition of a new species -Bosminopsis negrensis Brandorff (1976a) . Apparently there is another endemic species of Bosminopsis in Amazonia reported by Brandorff et al (1982) .…”

Composition, species richness and patterns of nycthemeral vertical distribution of planktonic cladocereans in a black water Amazonian lake

“…Bosminopsis negrensis and B. brandorffi were registered only during the high water period and both species are considered to be endemic to the Amazon basin (Brandorff, 1976;Rey and Vasquez, 1986).…”

Composition, abundance, and diversity of limnetic cladocerans (Crustacea: Anomopoda and Ctenopoda) in a black-water lake in the Negro River basin, Amazonas State, Brazil

“…Brandorff (1978) found that the most species-rich family in the Amazonian ecosystem was Bosminidae. Three Bosminidae species were observed, two of them endemic to the Amazon basin (Brandorff, 1976;Rey and Vásquez, 1989). Records of the genus Bosmina are common in many regions of Brazil, especially in reservoir environments (Paggi and José de Paggi, 1990;Lansac-Tôha et al, 2004;Perbiche-Neves and Nogueira, 2010).…”