Marcus A. B. Pires

Larval development of Lepidophthalmus siriboia Felder & Rodrigues, 1993 (Decapoda: Thalassinidea) from the Amazon region, reared in the laboratory

The complete larval development of the ghost shrimp Lepidophthalmus siriboia Felder & Rodrigues, 1993 was described and illustrated in detail from specimens reared in the laboratory. Ovigerous females were collected at Canela Island in the northeastern region of the State of Para. The larvae hatch as a prezoea, in which they persist for less than 3 hours. The larval development consists of three zoeal stages and a megalopa. The zoeal development averaged from 69 to 111 hours. The period in the megalopa stage was about 185 hours (about 8 days). The percentage of individuals succeeding in molt into juvenile stage was 91,8%. The first juvenile stage was reached 254 hours (about 10 days) after hatching. Morphological comparisons and their relationship with larvae of congeneric species are briefly discussed.

Occurrence of Cymbasoma longispinosum Bourne, 1890 (Copepoda: Monstrilloida) in the Curuçá River estuary (Amazon Littoral)

The present work was carried out to verify the occurrence and distribution of Cymbasoma longispinosum Bourne, 1890 in a tropical Amazon estuary from North Brazil. Samplings were performed bimonthly from July/2003 to July/2004 at two different transects (Muria and Curuca rivers) situated along the Curuca estuary (Para, North Brazil). Samples were collected during neap tides via gentle (1 to 1.5 knots) 200 μm-mesh net tows from a small boat. Additional subsurface water samples were collected for the determination of environmental parameters. Males and females of Cymbasoma longispinosum were only observed during September and November/2003. The highest number of organisms was found in September/2003 at the Muria River transect. The presence of C. longispinosum in samples obtained during September and November/2003 could probably be related to the reproductive period of this species in the studied estuary, which is directly related to the dry period in the region. The highest salinity values and the highest number of individuals observed in September/2003 corroborate with the previous assumption, since no C. longispinosum was found during the months comprising the rainy period (January to June).

A note on the occurrence of praniza larvae of Gnathiidae (Crustacea, Isopoda) on fishes from Northeast of Pará, Brazil

The infection of the estuarine teleost fishes Mugil gaimardianus Desmarest, 1831 (Mugilidae), Arius phrygiatus Valenciennes, 1839 (Ariidae), Conodon nobilis Linnaeus, 1759 (Haemulidae), Cetengraulis edentulus Cuvier, 1829 (Engraulidae), and Anableps anableps Linnaeus, 1758 (Anablepidae) by praniza larvae of Gnathiidae (Crustacea, Isopoda) was studied in specimens fished off the Atlantic Ocean in Northeast of Pará State, near Bragança, Brazil. The highest infection prevalence value was found in Anableps anableps (42.3%) and the lowest in Conodon nobilis (9.1%). The mean intensity varied from 1 parasitein Conodon nobilis to 19.5 in Arius phrygiatus. A description of the larvae is provided. The morphology of the mouthparts is related to the blood sucking activity, and is compared with the characteristics of other gnathiidae species.

Early larval development in the laboratory of Alpheus estuariensis (Crustacea: Caridea) from the Amazon Region

O presente estudo descreve e ilustra em detalhes os quatro primeiros estagios de Alpheus estuariensis Christoffersen, 1984 a partir de larvas cultivadas em laboratorio. Duas femeas ovigeras foram coletadas no canal de mare do estuario de Braganca, estado do Para, nordeste do Brasil. Apos a eclosao, as larvas foram colocadas em pequenos recipientes (com 10 larvas em cada). As femeas foram depositadas no Museu Paraense Emilio Goeldi (MPEG 0803) e as larvas de cada estagio larval no Museu zoologico da Universidade de Sao Paulo (MUSP18452). Foram dissecadas 10 larvas e exuvias com finas agulhas sob um microscopio ocular. Comparacoes morfologicas com outros estudos reportados sobre o desenvolvimento larval de especies de Alpheus sao brevemente discutidas.

The early larval development of the tropical reef lobster Enoplometopus antillensis Lütken (Astacidea, Enoplometopidae) reared in the laboratory

Os estagios iniciais da lagosta tropical Enoplometopus antillensis Lutken, 1865 foram descritos e ilustrados a partir de especimes cultivados em laboratorio. Femeas ovigeras foram capturadas em seu habitat, na profundidade cerca de 15 metros e transportadas para o laboratorio. As larvas foram cultivadas em tanques de agua recirculante por aproximadamente 15 dias e, entao transferidas para quatro aquarios (capacidade 10 litros). As larvas foram alimentadas com nauplios de Artemia sp. recem eclodidos. A microalga Dunaliella viridis AUTOR foi diariamente adicionada no cultivo. As larvas mudaram sete vezes alcancando o zoea VIII. O estagio megalopa nao foi obtido. O periodo de intermuda de cada estagio variou de cerca de oito a 12 dias. Comparacoes morfologicas com trabalhos anteriores sao brevemente discutidas.