First zoeal stage of the hermit crab Enallopaguropsis guatemoci (Glassell, 1937) (Crustacea: Anomura: Paguroidea: Paguridea) obtained in the laboratory

Zootaxa ◽  
2017 ◽  
Vol 4227 (3) ◽  
pp. 359
Author(s):  
MANUEL AYÓN-PARENTE ◽  
MICHEL E. HENDRICKX
Keyword(s):  

The first larval stage of Enallopaguropsis guatemoci is described in detail and illustrated. The larva is compared with larvae known for other genera of Paguridae except Pagurus. A synthesis of all characters provided herein indicates that first larvae of E. guatemoci can be separated from all known pagurid larvae (except Pagurus) by the combination of the following characters: carapace with long dorsal carina, posterolateral spines absent; abdominal somites 3–5 with pair of moderately long spines; telson narrowly triangular, not forked; spine at antennal protopod as long as endopod. 

Author(s):  
Ricardo Calado ◽  
Natacha Nogueira ◽  
Antonina dos Santos

The present work reports the existence of extended parental care in a hermit crab species of the genus Calcinus. The species shows a high energetic investment in egg production, only producing one to six large-sized eggs. The larval development is extremely abbreviated, with the larvae hatching at an advanced zoeal stage, a rather uncommon feature among marine and non-symbiotic decapods. The sequential moults end in a glaucothoe-type larval stage that is retained inside the female's host gastropod shell, probably in complete lecithotrophy. The high maternal reproductive investment displayed by this species is certainly maximized through the retention of juveniles until they enter a suitable gastropod shell, since it considerably reduces the chances of intra- or interspecific predation.


Zootaxa ◽  
2020 ◽  
Vol 4838 (1) ◽  
pp. 71-82
Author(s):  
RAFAEL C. SANTOS ◽  
RÉGIS A. PESCINELLI ◽  
ROGERIO C. COSTA

Herein, the Zoea I of Synalpheus apioceros is described, followed by a comparative analysis of the first larval stage from Synalpheus. Larvae were obtained from two ovigerous females sampled in Ubatuba, São Paulo. The morphology of the Zoea I of S. apioceros was compared to five other Synalpheus species whose structures were previously described: S. biunguiculatus, S. minus, S. neomeris, S. pectiniger, and S. tumidomanus. A set of unique morphological characteristics was found for S. apioceros: exopod of antennule with 4 aesthetascs and 1 plumose seta; coxal endite of maxillule with 2 simple setae plus 2 plumose setae; basial endite of maxillule with 2 simple setae plus 2 short spines; endopod of maxillule with 1 plumose seta plus 2 simple setae; basial endite of maxilla bilobed with 2 (1 plumose and 1 simple) + 2 (1 plumose and 1 simple) setae; coxal endite of maxilla bilobed with 2 + 1 plumose setae; endopod of maxilla with 3 (1 plumose and 2 simple) terminal setae + 2 simple setae; endopod of first maxilliped unsegmented with 3 terminal simple setae; basis of first maxilliped with 5 spines; endopod of second maxilliped 5-segmented with 0, 0, 0, 1 plumodenticulate, 4 (1 serrate + 3 simple) setae; endopod of third maxilliped 5-segmented with 0, 0, 0, 1 simple, 3 simple setae; pereiopods 1st to 3rd birramous and 4th and 5th uniramous. S. apioceros shows higher morphological similarity with S. minus, followed by S. tumidomanus, S. neomeris and S. pectiniger, probably since these species present extended larval development. Besides the similar morphology among species, the unique attributes presented here are important for the genus’ taxonomy, being fundamental for identifying the first larval stages of Synalpheus, as well as for subsidizing information for species identification keys. 


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
João Alberto Farinelli Pantaleão ◽  
Fernando Luis Mantelatto ◽  
Rogério Caetano Costa

Abstract: A complete and detailed description of the first zoeal stage of Ogyrides occidentalis is provided. Larvae were obtained in the laboratory from a female with embryos collected in Ubatuba, State of São Paulo, Brazil. The morphological characters are compared with previous description of the close related O. alphaerostris. Despite of some similarities (number of appendages, pleonites, and setae on the majority of appendages) substantial differences were found between the two species, as the size of larvae and rostrum and segmentation of some structures (antenna exopod, first maxilliped coxa and basis). However, these differences must be interpreted carefully because larval description of O. alphaerostris was conducted before the proposed standardization for decapod larval morphology descriptions. The present larval description furnished additional information to corroborate the recent resurrection of O. occidentalis and will be useful for future comparative and ecological research.


Biologia ◽  
2010 ◽  
Vol 65 (4) ◽  
Author(s):  
Somasundaran Lyla ◽  
Ajmal Khan

AbstractThe levels of heavy metals copper and zinc were found to be high in the Vellar estuary. Therefore their effects on the larval development of the abundant hermit crab Clibanarius longitarsus were studied individually and in combination from hatching till moulting to glaucothoe stage in the laboratory using freshly hatched Artemia nauplii as food. The 96 h LC50 values found with 100 larvae each kept in 10 different concentrations of copper and zinc (350, 300, 250, 200, 150, 100, 50, 25, 10 and 5 ppb) were 50 ppb for copper and 90 ppb for zinc. Based on these 96 h LC50 values, three sublethal concentrations were chosen for the metals copper and zinc at 50%, 25% and 10% levels of the LC50 values. With increase in concentration of the test medium, the survival rate decreased and the time required for the completion of each zoeal stage increased. Copper was found to be more toxic than zinc as the survival rate in copper concentrations was lower than those in zinc concentrations. The survival rate in the mixed concentrations of metals was lower than in individual concentrations.


Author(s):  
Eric Hallberg ◽  
Lina Hansén

The antennal rudiments in lepidopterous insects are present as disks during the larval stage. The tubular double-walled antennal disk is present beneath the larval antenna, and its inner layer gives rise to the adult antenna during the pupal stage. The sensilla develop from a cluster of cells that are derived from one stem cell, which gives rise to both sensory and enveloping cells. During the morphogenesis of the sensillum these cells undergo major transformations, including cell death. In the moth Agrotis segetum the pupal stage lasts about 14 days (temperature, 25°C). The antennae, clearly seen from the exterior, were dissected and fixed according to standard procedures (3 % glutaraldehyde in 0.15 M cacaodylate buffer, followed by 1 % osmiumtetroxide in the same buffer). Pupae from day 1 to day 8, of both sexes were studied.


2017 ◽  
Vol 23 (2) ◽  
Author(s):  
SHASHI KIRAN

The objective of this study was to determine the relationship of C. fasciolaris with common rats. Cysticercus fasciolaris is the larval stage of Taenia taeniaeformis . Development of metacestodes ( Cysticercus fasciolaris) occur in the liver of rodents. An urban and a sylvatic cycle occurs. A total of 40 liver specimens of rats were examined. Histopathological examination revealed the presence of multiple hepatic cysts, and the C. fasciolaris larva was surrounded by granulation tissue. Large and separated ûbroblasts in different orientations with some neoplastic changes were seen in advanced hepatic cysticercosis. The bladder involved the larva and large chamber containing the small chamber and opalescent fluid. The scolex of the mature larva is distinctly large, bearing four lateral distinct suckers, a rostellum armed with double, and alternating rows of hooks.


Author(s):  
Judith Fuchs

This chapter describes the taxonomy of Phoronida, a small group of exclusively marine invertebrates found in most of the world's oceans from the intertidal zone to about 400 metres depth. Phoronids are meroplanktonic with a planktonic larval stage usually less than 2 mm in length and a benthic adult whose length ranges from a few cm up to 50 cm. The chapter covers their life cycle, ecology, and general morphology. It includes a section that indicates the systematic placement of the taxon described within the tree of life, and lists the key marine representative illustrated in the chapter (usually to genus or family level). This section also provides information on the taxonomic authorities responsible for the classification adopted, recent changes which might have occurred, and lists relevant taxonomic sources.


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