Migration and reproductive biology of Mugil liza (Teleostei: Mugilidae) in south Brazil

2014 ◽  
Vol 85 (3) ◽  
pp. 671-687 ◽  
Author(s):  
V. M. Lemos ◽  
A. S. Varela ◽  
P. R. Schwingel ◽  
J. H. Muelbert ◽  
J. P. Vieira
2008 ◽  
Vol 25 (3) ◽  
pp. 403-412 ◽  
Author(s):  
Patrícia Calil ◽  
Carlos A. Borzone

Mysidacea are common sublittoral crustaceans that inhabit all coasts in the world. In this study, the population characteristics and the reproductive biology of Metamysidopsis neritica Bond-Buckup & Tavares, 1992 were studied in the surf zone of a south Brazilian beach (Atami). Mysids were sampled at monthly intervals from August, 1999 to July, 2000 (total of 29,490 individuals). Individuals were classified into six population categories. The highest abundance occurred in May (8,665) and August (6,415), and lowest in September (336) and December (368). Three main generations were identified, namely the summer, fall and winter generations. The winter generation was the longest (four to five months). The fall generation lasted four months, and the summer one extended from three to four months. Ovigerous females occurred throughout the year, with a greater proportion in July. The number of eggs or larvae varied from one to 16. Weak associations were found between female length and egg number, egg volume, and the number of larvae with and without eyes. Egg volume increased during the coldest season, whereas the smallest values were recorded during summer. These results suggest a possible direct relationship between egg volume and generation longevity.


2017 ◽  
Vol 65 (3) ◽  
pp. 225 ◽  
Author(s):  
A. H. Krahl ◽  
D. R. P. Krahl ◽  
J. J. Valsko ◽  
A. C. Webber ◽  
E. R. Pansarin

Encyclia is a neotropical orchid genus distributed from Florida to South Brazil and comprises ~120 taxa, including Encyclia mapuerae (Huber) Brade & Pabst. Besides its diversity and wide distribution, conclusive data on pollinators and reproductive biology of this orchid genus is scarce. Furthermore, nothing is known about the production of floral reward in Encyclia but the pollinators of their species are assumed to be attracted through food deception. Based on data on phenology, floral morpho-anatomy, histochemistry, pollinators, pollination mechanisms, and breeding system, the reproductive biology of E. mapuerae was studied in a nature reserve at Central Amazonia, Brazil. The flowers of E. mapuerae show longitudinal lines on the labellum that act as a nectar guide. The secretory epidermis has papillae whose cells are covered by an ornamented cuticle. The subtended tissue is composed of a tree-layered collenchyma. The flowers attract several species of Hymenoptera. However, a single species of Centris was recorded as pollinator. The bees collect the nectar produced inside the cuniculus. When the bees leave the flower the pollinarium is attached to their heads. Encyclia mapuerae is self-compatible and pollinator-dependent. The reproductive success in natural conditions is low because of deficient pollen transference due to the scarcity of pollinators. As far we know this is the first study that reports and production of floral reward in Encyclia. This discovery provides new insights on the function of the cuniculus in Laeliinae, and sheds light on the evolution of floral rewards and pollination mechanisms within this diverse group of Neotropical orchids.


Scientifica ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-16
Author(s):  
Hélio Augusto Alves Fracasso ◽  
Joaquim Olinto Branco ◽  
Márcio Amorim Efe ◽  
João Pedro Barreiros

In this work, we intend to describe the reproductive dynamics ofSterna hirundinaceain an island from South Brazil. We studied the reproductive biology of this species in its natural environment and provide data on their growth, survival, and reproductive success in Ilha dos Cardos, Santa Catarina, South Brazil. Samplings were carried out daily on the island throughout the reproductive seasons of 2003, 2005, and 2006 and the different stages of development of the chicks were characterized according to age, length of the beak, and plumage characteristics. We provide a basic equationLm=167.91 (1-e-0.062t--0.23)to determine the approximate age of individuals using their body mass. The main cause of chick mortality on the island was natural (63.17% in 2003, 81.41% in 2005, and 79.96% in 2006), whereas predation contributed to mortality in a proportion of 38.83% in 2003, 18.59% in 2005, and 20.04% in 2006. The absence in the area of the chicks’ main predator, Kelp gull (Larus dominicanus), the large number of chicks that reached the final stages of development, and their reproductive success demonstrate that Ilha dos Cardos is an important breeding site for the species in southern Brazil.


2016 ◽  
Vol 98 (4) ◽  
pp. 329-339 ◽  
Author(s):  
Luiza Loebens ◽  
Sonia Zanini Cechin ◽  
Tiago Felipe Theis ◽  
Livia Bataioli Moura ◽  
Selma Maria Almeida-Santos

2017 ◽  
Vol 99 (2) ◽  
pp. 105-114 ◽  
Author(s):  
Luiza Loebens ◽  
Claudio Augusto Rojas ◽  
Selma Maria Almeida-Santos ◽  
Sonia Zanini Cechin

Author(s):  
Alan N. Hodgson

The hermaphrodite duct of pulmonate snails connects the ovotestis to the fertilization pouch. The duct is typically divided into three zones; aproximal duct which leaves the ovotestis, the middle duct (seminal vesicle) and the distal ovotestis duct. The seminal vesicle forms the major portion of the duct and is thought to store sperm prior to copulation. In addition the duct may also play a role in sperm maturation and degredation. Although the structure of the seminal vesicle has been described for a number of snails at the light microscope level there appear to be only two descriptions of the ultrastructure of this tissue. Clearly if the role of the hermaphrodite duct in the reproductive biology of pulmonatesis to be understood, knowledge of its fine structure is required.Hermaphrodite ducts, both containing and lacking sperm, of species of the terrestrial pulmonate genera Sphincterochila, Levantina, and Helix and the marine pulmonate genus Siphonaria were prepared for transmission electron microscopy by standard techniques.


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