scholarly journals Transformative nototchaetae: larval development and metamorphosis in Chrysopetalum spp. (Chrysopetalinae: Chrysopetalidae: Annelida)

Zoosymposia ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 209-221
Author(s):  
CHARLOTTE WATSON
Keyword(s):  
Larval Development ◽  
Developmental Processes ◽  
Planktotrophic Larva ◽  
Longitudinal Ribs ◽  
Larval Stages ◽  
Larvae And Juveniles ◽  
Sensory Structures

The morphology of an early nectochaete larva belonging to Chrysopetalum sp. is aligned with that of a planktotrophic larva at a crucial stage of benthic settlement: an entire provisional spinose notochaetal scleritome, large episphere with prostomial nascent sensory structures and larval podia and cirri of the anterior two segments in transition. Morphological sequences of post-larvae and juveniles, common to a number of Chrysopetalum species, indicate that long, slender, provisional, camerate notochaetal spines are replaced during metamorphosis and growth with an entire adult, camerate notochaetal scleritome consisting of broad paleae with internal, longitudinal ribs. The Chrysopetalum sp. six segment larva supports achaetous notopodia I and chaetous notopodia II, each with a pair of dorsal cirri, ie. 4 cirri in total; segment II has acirrose neuropodia. Individuals of post-larvae and juvenile Chrysopetalum species, 8–15 segments, possess a total of 6 cirri on segments I and II: segment I with a pair of tentacular dorsal cirri and the formation of a pair of tentacular ventral cirri, and segment II comprising a pair of dorsal cirri, spinous notochaetae and acirrose neuropodia. During metamorphosis the acirrous neuropodia of segment II are reabsorbed and replaced in stages with a pair of ventral tentacular cirri until the adult state is achieved: achaetous segment 1 with two pairs of tentacular cirri and segment II similar, ie. total of 8 cirri. The cirri arrangement of segments I and II before final metamorphosis in post-larval stages of Chrysopetalum species is, interestingly, that described for adults in the majority of other Chrysopetalinae taxa. Ontogenetic developmental processes of formation and loss of acirrose neuropodia and replacement of spinose larval notochaetae with adult paleae observed in Chrysopetalum species are compared with species of other taxa of the Chrysopetalinae.

Development of Camallanus adamsi Bashirullah, 1974 (Nematoda: Camallanidae) in cyclopoid copepods

1976 ◽  
Vol 54 (12) ◽  
pp. 2055-2060 ◽  
Author(s):  
A. K. M. Bashirullah ◽  
Benazir Ahmed
Keyword(s):  
Larval Development ◽  
Intermediate Hosts ◽  
Larval Stages ◽  
Mesocyclops Leuckarti

The larval development of Camallanus adamsi Bashirullah, 1974 was followed in intermediate hosts, Mesocyclops leuckarti (Claus) and Thermocyclops crassus (Fischer), which were kept at 24 °C and 27 °C (average). The nematode molted twice in the haemocoel of copepods. The first molt occurred 117 h after infection at 24 °C and the second molt after 249 h. At 27 °C, the first and the second molts occurred 72 and 168 h respectively after the infection. Three larval stages are described.

Neurogenesis in the thoracic neuromeres of two crustaceans with different types of metamorphic development

1998 ◽  
Vol 201 (17) ◽  
pp. 2465-2479 ◽  
Author(s):  
S Harzsch ◽  
J Miller ◽  
J Benton ◽  
RR Dawirs ◽  
B Beltz
Keyword(s):  
Embryonic Development ◽  
Larval Development ◽  
Neuronal Development ◽  
Temporal Patterns ◽  
Homarus Americanus ◽  
Spider Crab ◽  
Larval Life ◽  
Larval Stages ◽  
Metamorphic Development ◽  
Embryonic And Larval Development

The mode of embryonic and larval development and the ethology of metamorphosis in the spider crab and the American lobster are very different, and we took advantage of this to compare neuronal development in the two species. The goals of this study were to discover whether the differences in the maturation of the neuromuscular system in the pereopods and the metamorphic changes of motor behavior between the two species are reflected at the level of the developing nervous system ('neurometamorphosis'). Furthermore, we wanted to broaden our understanding of the mechanisms that govern neuronal development in arthropods. Proliferation of neuronal stem cells in thoracic neuromeres 4-8 of the lobster Homarus americanus and the crab Hyas araneus was monitored over the course of embryonic and larval development using the in vivo incorporation of bromodeoxyuridine (BrdU). Neuropil structure was visualized using an antibody against Drosophila synapsin. While proliferation of neuronal precursors has ceased when embryogenesis is 80 % complete (E80%) in the lobster thoracic neuromeres, proliferation of neuroblasts in the crab persists throughout embryonic development and into larval life. The divergent temporal patterns of neurogenesis in the two crustacean species can be correlated with differences in larval life style and in the degree of maturation of the thoracic legs during metamorphic development. Several unusual aspects of neurogenesis reported here distinguish these crustaceans from other arthropods. Lobsters apparently lack a postembryonic period of proliferation in the thoracic neuromeres despite the metamorphic remodeling that takes place in the larval stages. In contrast, an increase in mitotic activity towards the end of embryonic development is found in crabs, and neuroblast proliferation persists throughout the process of hatching into the larval stages. In both E20% lobster embryos and mid-embryonic crabs, expression of engrailed was found in a corresponding set of neurons and putative glial cells at the posterior neuromere border, suggesting that these cells have acquired similar specific identities and might, therefore, be homologous. None of the BrdU-labeled neuroblasts (typically 6-8 per hemineuromere over a long period of embryogenesis) was positive for engrailed at this and subsequent stages. Our findings are discussed in relation to the spatial and temporal patterns of neurogenesis in insects.

scholarly journals Morphological development of larvae and juveniles of Prochilodus argenteus

2017 ◽  
Vol 47 (4) ◽  
Author(s):  
Irũ Menezes Guimarães ◽  
◽  
Vinícius Augusto Dias Filho ◽  
Ana Helena Gomes da Silva ◽  
Rafael Silva Santos ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Linear Regression Analysis ◽  
The Body ◽  
Morphological Development ◽  
Body Proportions ◽  
Juvenile Phase ◽  
Larval Stages ◽  
Larvae And Juveniles ◽  
Rate Of Increase ◽  
Environmental Importance

ABSTRACT: Prochilodus argenteus is an endemic fish species from the São Francisco River basin that is of high economic and environmental importance. The present study aimed to contribute with information to the taxonomic identification of larvae and juveniles of this species. Larvae , obtained from induced spawning of wild animals, were reared in ponds. Individuals were collected daily and classified into larval stages or juvenile phase. Morphological descriptions and morphometric measurements were performed, together with a piece wise linear regression analysis of the body proportions throughout the development process. Individuals in the preflexion stage had a standard length (SL) of 4.48 to 6.64mm, long to moderate body (BH/SL), small to moderate head (HL/SL), and a small to moderate eye (ED/HL). In the flexion stage, the SL varied from 6.60 to 11.00mm, long to moderate body, moderate head, and small to moderate eye. Larvae in the postflexion stage presented SL of 10.54-19.93mm, moderate body, moderate to big head and small eye. The juvenile phase included specimens with a SL of 18.27 to 42.21mm which presented a moderate to high body, big head and small to moderate eye. Regression analysis showed significant moments of change in rate of increase of the body proportions, presenting a change in the growth pattern from allometry to isometry during the early development.

Larval development of the stygobitic shrimp Creaseria morleyi (Creaser, 1936) (Decapoda: Caridea: Palaemonidae) from the Yucatán Peninsula, Mexico

2020 ◽  
Vol 40 (3) ◽  
pp. 221-229
Author(s):  
Sergio A Benítez ◽  
Thomas M Iliffe ◽  
Salvador Martínez ◽  
Juan Carlos Ojeda ◽  
José Luis Villalobos ◽  
...  
Keyword(s):  
Larval Development ◽  
Yucatan Peninsula ◽  
Juvenile Stage ◽  
Quintana Roo ◽  
Stages Of Development ◽  
Larval Stages ◽  
Yucatán Peninsula ◽  
Anchialine Caves

Abstract Although the larval development of epigean palaemonid shrimps has been studied extensively, only a few investigations deal with stygobitic species. We present the larval development of the cave-adapted Creaseria morleyi (Creaser, 1936) from anchialine caves in the Tulum area, Quintana Roo, Yucatán Peninsula, Mexico. Through the discovery of a series of larvae at different stages of development, we constructed a sequence extending through the juvenile stage. The larvae (41) were captured in plankton tows above the halocline at depths ranging between 11 and 15 m during eight surveys conducted between 2013 and 2016. Six larval stages and the first juvenile were identified; however, it is clear from the gradual modification of structures and appendages that more stages exist. The first larvae have a large quantity of vitellum and do not feed, since they have only rudimentary, and possibly non-functional, mouthparts. In the sixth stage and the juvenile, when the stages have no vitellum left, the mouthparts, chelae, and pleopods develop entirely. A comparison with other palaemonid shrimps suggests that C. morleyi has a greater affinity with those palaemonid species possessing extended larval development as is seen in species of MacrobrachiumSpence Bate, 1868.

scholarly journals Development and functional morphology of the larval foregut of two brachyuran species from Northern Brazil

2011 ◽  
Vol 83 (4) ◽  
pp. 1269-1278 ◽  
Author(s):  
Fernando A. Abrunhosa ◽  
Darlan J.B. Simith ◽  
Joely R.C. Monteiro ◽  
Antonio N. de Souza Junior ◽  
Pedro A.C. Oliva
Keyword(s):  
Larval Development ◽  
Feeding Behaviour ◽  
Food Source ◽  
Morphological Structure ◽  
Filter Press ◽  
Larval Feeding ◽  
Structural Development ◽  
Gastric Mill ◽  
Larval Stages ◽  
Northern Brazil

Feeding is an important factor for the successful rearing of larvae of the crab species. Further information on the morphological features of the foregut may to reveal larval feeding behaviour and or/whether there is a lecithotrophy in some or even in all stages of the larval cycle. In the present study, the structural development of the foregut and their digestive functions were examined in larvae of two brachyurans, Uca vocator and Panopeus occidentalis, reared in the laboratory. During larval development, the foreguts of the larvae in the first and last zoeal stages and in the megalopa stage were microscopically examined, described and illustrated. The zoeal foreguts of both species were well developed, showing specialization with a functional cardiopyloric valve and a filter press. The megalopa stage had a complex and specialized gastric mill similar to that found in adult crabs with the appearance of rigidly calcified structures. These results support the hypothesis that the feeding behaviour of each larval stage is directly related to the morphological structure of the foregut. Such facts strongly indicate that all larval stages of both . vocator and P occidentalis need an external food source before completing the larval development in a planktonic environment.

scholarly journals A new Synbranchus (Teleostei: Synbranchiformes: Synbranchidae) from ilha de Marajó, Pará, Brazil, with notes on its reproductive biology and larval development

2005 ◽  
Vol 3 (3) ◽  
pp. 319-328 ◽  
Author(s):  
Sandra E. Favorito ◽  
Angela M. Zanata ◽  
Maria I. Assumpção
Keyword(s):  
New Species ◽  
Larval Development ◽  
Reproductive Biology ◽  
Color Pattern ◽  
The Other ◽  
Larval Stages ◽  
Marajó Island ◽  
Northern Brazil

Synbranchus lampreia, new species, is described from rio Goiapi, Marajó Island, Pará, northern Brazil. It differs from the other two described species of the genus by its color pattern, which consists of large roundish black blotches scattered over a light brown or yellowish ground pigmentation and presence of inconspicuous brown small spots distributed among the large dark spots. The species is further distinguished from S. marmoratus by a higher number of vertebrae and from S. madeira by a shorter postanal length. Information about reproductive aspects is provided and larval stages are described and illustrated.

Embryonic and larval development of the caridean shrimp Palaemon argentinus (Decapoda, Caridea): effects of salinity and diet

Crustaceana ◽  
2021 ◽  
Vol 94 (1) ◽  
pp. 45-62
Author(s):  
Carolina Tropea ◽  
Liane Stumpf ◽  
Laura S. López Greco
Keyword(s):  
Larval Development ◽  
Artemia Salina ◽  
Culture Conditions ◽  
Nutritional Requirements ◽  
Larval Performance ◽  
Larval Rearing ◽  
Caridean Shrimp ◽  
Natural Habitats ◽  
Larval Stages ◽  
Wide Range

Abstract The caridean shrimp Palaemon argentinus is a species of commercial and ecological interest. Its numerous larval stages, the lack of knowledge on their nutritional requirements, and their ability to survive in a wide range of salinities raise questions on the optimum conditions for larval rearing in captivity. The present study was aimed at evaluating embryonic development under different salinities and larval development under different combinations of salinities and diet regimes, in order to define alternative, cheaper culture conditions. We tested salinities usually encountered by the species in natural habitats (0.1, 1 and 5 ppt) and a highly protein-inert diet (Tetracolor®) as a potential replacement for live food (nauplii of Artemia salina). The incubation period and fecundity were similar among salinity treatments. Overall, the number of survival days and percentage of zoeae that moulted two, three and four times were higher when embryogenesis occurred at 5 ppt and when larvae were exposed to 5 ppt. These results suggest that the conditions experienced by embryos affect the performance of the first larval stages, and probably reflect the lower energetic requirements of zoeae to osmoregulate as water and haemolymph osmolarity become closer. On the other hand, larval performance was better when fed A. salina nauplii than Tetracolor®. The latter may not cover the nutritional requirements of zoeae or may have low digestibility due to insufficient enzymes in the undeveloped larval digestive system. Based on the present results, we conclude that a salinity of 5 ppt combined with a diet consisting of Artemia sp. nauplii is optimal for larval culture at early stages.

scholarly journals Effect of body size heterogeneity on the aggressive behavior of larvae of matrinxã, Brycon amazonicus (Characiformes, Bryconidae)

2018 ◽  
Vol 48 (4) ◽  
pp. 304-310 ◽  
Author(s):  
Thaís Billalba CARVALHO ◽  
Ellen Cristina Monteiro de SOUZA ◽  
Jaquelinne PINHEIRO-DA-SILVA ◽  
Marle Angélica VILLACORTA-CORREA
Keyword(s):  
Body Size ◽  
Aggressive Behavior ◽  
Larval Development ◽  
Production Systems ◽  
Larval Mortality ◽  
Development Stage ◽  
Breeding Systems ◽  
Aggressive Interactions ◽  
Larval Stages ◽  
Size Heterogeneity

ABSTRACT Brycon amazonicus is a native Amazonian fish that is important for aquaculture in South America. Larval mortality is high in this species in intensive breeding systems due to aggressiveness among larvae. The present study investigated experimentally the effects of body size heterogeneity on the aggressive behavior and survival of B. amazonicus during the early stages of larval development. Two treatments (larvae groups with homogeneous and heterogeneous body size) were evaluated throughout early larval stages tested at six time points: 12, 24, 36, 48, 60 and 72 hours after hatching (HAH). Two experiments quantified, respectively, aggressive interactions and mortality rates among larvae at each time point. The frequency of aggressive interactions exhibited by the less aggressive larvae in each replicate was higher in the homogeneous size treatment. Aggressiveness was higher at 12 HAH, decreasing thereafter, and increasing again at 72 HAH. The mortality rate significantly increased with the larval stage, and was higher in the homogeneous than in the heterogeneous sized groups. Our results showed that aggressiveness in B. amazonicus larvae is affected by size variability and larval development stage. This knowledge about larval behavior is important to develop measures to improve larval health and survival in intensive production systems for this species.

Larval development of Petrolisthes tuberculatus (Guérin, 1835) (Decapoda, Anomura, Porcellanidae) reared in laboratory

Zootaxa ◽  
2019 ◽  
Vol 4623 (2) ◽  
pp. 364-380
Author(s):  
MARIA EUGENIA GONZALEZ-CANALES ◽  
JOSE A. CUESTA ◽  
JUAN IGNACIO GONZÁLEZ-GORDILLO
Keyword(s):  
Larval Development ◽  
The Other ◽  
Larval Stages ◽  
First Time

The complete larval development of Petrolisthes tuberculatus (including two zoeal stages and the megalopa) is described and illustrated in detail for the first time, based on laboratory-reared material. In order to allow the differentiation of specimens from plankton samples, the larval stages of P. tuberculatus are compared with those known for other porcellanid crabs from Chilean waters (Allopetrolisthes angulosus, Petrolisthes granulosus, P. laevigatus and P. violaceus). As expected, this comparison lead to the inclusion of P. tuberculatus within the “sección Porcellanina” together with the other Chilean species of porcellanids. 

The complete description of larval stages of the lobster shrimpLeonardsaxius amurensis(Kobjakova, 1937) (Decapoda: Axiidea: Axiidae) identified by DNA barcoding

2017 ◽  
Vol 98 (6) ◽  
pp. 1435-1453 ◽  
Author(s):  
Elena S. Kornienko ◽  
Darya D. Golubinskaya ◽  
Olga M. Korn ◽  
Svetlana N. Sharina
Keyword(s):  
Larval Development ◽  
Sequence Data ◽  
Molecular Genetic ◽  
Sympatric Species ◽  
Molecular Genetic Analysis ◽  
Mitochondrial Coi ◽  
Larval Stages ◽  
The Family ◽  
Rdna Sequence Data ◽  
First Time

The complete larval development of the lobster shrimpLeonardsaxius amurensis(Kobjakova, 1937) (Decapoda: Axiidea: Axiidae) is described and illustrated for the first time. The first zoeae of this species were collected from the plankton samples and reared in the laboratory before moulting to the megalopa. A molecular genetic analysis based on comparison of partial mitochondrial COI, 12S rDNA and 16S rDNA sequence data confirmed the identity of axiid larvae found in the plankton andL. amurensisadults collected in the same area. The larval development ofL. amurensisincludes five zoeal stages and a single megalopa. Zoeae I ofL. amurensisare characterized by the presence of one short posterodorsal spine on the fifth pleonite in contrast to the larvae of related sympatric speciesBoasaxius princepshaving four posterodorsal spines on the pleonites 2–5.Leonardsaxius amurensisoccupies an intermediate position between lobster shrimps with abbreviated pelagic development (2–3 zoeal stages) and species with long development (up to eight zoeal stages). Thus, the number of zoeal stages in the family Axiidae varies widely, similarly to that in the families Callianassidae and Upogebiidae.

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