New Record and Biology of the Molly Poecilia sphenops (Poeciliidae), Discovered in the Northern Sahara of Algeria

Ghazi, Cherif; Bachir, Abdelkrim Si; Idder, Tahar

doi:10.1134/s0032945219040039

Cited by 3 publications

(1 citation statement)

References 21 publications

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“…They live in freshwater streams but were also recorded in the coastal waters of Mexico [ 3 ]. Due to their diurnal nature, mollies are active during the day and sleep at night [ 23 ]. The Poeciliidae family is considered an ideal system for studying relationships between visual acuity and visual signals.…”

Section: Introductionmentioning

confidence: 99%

Retinal Structure of Poecilia sphenops: Photoreceptor Mosaics, Synaptic Ribbon Patterns, and Glial Cell Expressions

Mokhtar,

Albano,

Alonaizan

et al. 2024

Animals

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The specific arrangement and distribution of photoreceptors in the retina can vary among different fish species, with each species exhibiting adaptations related to its habitat, behavior, and visual requirements. Poecilia sphenops, a diurnal fish, was the focus of this study. The retinas of a total of eighteen Molly fish were investigated utilizing light and electron microscopy. The retina exhibited a square mosaic pattern of the inner segments of cones. This pattern comprised double cones positioned along the sides of a square, with two types of single cones situated at the center and corners of the square arrangement across the entire retina. The corner cones were slightly shorter than the central ones. Additionally, the outer plexiform layer contained both cone pedicles and rod spherules. The rod spherule consisted of a single synaptic ribbon arranged in a triad or quadrat junctional arrangement within the invaginating free ends of the horizontal and bipolar cell processes. On the other hand, cone pedicles have more than one synaptic ribbon in their junctional complex. The inner nuclear layer consisted of the amacrine, bipolar, Müller, and horizontal cell bodies. Müller cell processes, expressing GFAP, extended across all retinal layers, segmenting the deeper retina into alternating fascicles of optic axons and ganglion cells. The outer and inner plexiform layers showed many astrocyte cell processes expressing GFAP. In conclusion, the current study is the first record of the retinal structures of Molly fish. This study illustrated the mosaic arrangement of photoreceptors and GFAP expression patterns of astrocytes and Müller cells. The presence of three cone types, coupled with a sufficient number of rods, likely facilitates motion awareness for tasks like finding food and performing elaborate mating ceremonies.

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Section: Introductionmentioning

confidence: 99%

Retinal Structure of Poecilia sphenops: Photoreceptor Mosaics, Synaptic Ribbon Patterns, and Glial Cell Expressions

Mokhtar,

Albano,

Alonaizan

et al. 2024

Animals

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Neuron mapping in the Molly fish optic tectum: An emphasis on the adult neurogenesis process

Hussein,

Sayed,

Mokhtar

2024

Microscopy Res & Technique

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Teleost fish exhibit the most pronounced and widespread adult neurogenesis. Recently, functional development and the fate of newborn neurons have been reported in the optic tectum (OT) of fish. To determine the role of neurogenesis in the OT, this study used histological, immunohistochemical, and electron microscopic investigations on 18 adult Molly fish specimens (Poecilia sphenops). The OT of the Molly fish was a bilateral lobed structure located in the dorsal part of the mesencephalon. It exhibited a laminated structure made up of alternating fiber and cellular layers, which were organized into six main layers. The stratum opticum (SO) was supplied by optic nerve fibers, in which the neuropil was the main component. Radial bipolar neurons that possessed bundles of microtubules were observed in the stratum fibrosum et griseum superficiale (SFGS). Furthermore, oligodendrocytes with their processes wrapped around the nerve fibers could be observed. The stratum album centrale (SAC) consisted mainly of the axons of the stratum griseum centrale (SGC) and the large tectal, pyriform, and horizontal neurons. The neuronal cells of the SO and large tectal cells of the SAC expressed autophagy‐related protein‐5 (APG5). Interleukin‐1β (IL‐1β) was expressed in both neurons and glia cells of SGC. Additionally, inducible nitric oxide synthase (iNOS) was expressed in the neuropil of the SAC synaptic layer and granule cells of the stratum periventriculare (SPV). Also, transforming growth factor beta (TGF‐β), SRY‐box transcription factor 9 (SOX9), and myostatin were clearly expressed in the proliferative neurons. In all strata, S100 protein and Oligodendrocyte Lineage Transcription Factor 2 (Olig2) were expressed by microglia, oligodendrocytes, and astrocytes. In conclusion, it was possible to identify different varieties of neurons in the optic tectum, each with a distinct role. The existence of astrocytes, proliferative neurons, and stem cells highlights the regenerative capacity of OT.Research Highlights The OT of the Molly fish exhibited a laminated structure made up of alternating fiber and cellular layers, which were organized into six main layers. Radial bipolar neurons that possessed bundles of microtubules were observed in the stratum fibrosum et griseum superficiale (SFGS). The stratum album central (SAC) consisted mainly of the axons of the stratum griseum centrale (SGC) and the large tectal, pyriform, and horizontal neurons. Inducible nitric oxide synthase (iNOS) was expressed in the neuropil of the SAC synaptic layer and granule cells of the stratum periventricular (SPV). Also, transforming growth factor beta (TGF‐β), SRY‐box transcription factor 9 (SOX9), and myostatin were clearly expressed in the proliferative neurons. The existence of astrocytes, proliferative neurons, and stem cells highlights the regenerative capacity of OT.

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A systematic review of poecilid fish invasions in Africa

Cairns,

de Bragança,

South

2024

Preprint

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Background. This review compiles and synthesises the existing information concerning non-native poecillid introductions to Africa. The recent upsurge in research on invasive poeciliids has revealed their widespread occurrence in Africa. Results. Within the 87 relevant articles, 74% reported on the presence Gambusia spp., 33% on P. reticulata, 19% on X. hellerii, 11% on X. maculatus, and 5% on other ornamental poeciliids. Overall, poeciliids have been introduced to 25 different countries in Africa, with Gambusia spp. being introduced to 16 countries and P. reticulata to 19 countries. Our results are representative of the current state of research on invasive poecilids in Africa. In particular there was a concentration of studies in South Africa, with limited research elsewhere. Current distribution data is relatively patchy, although widespread surveys of multiple river systems in Morocco and South Africa, confirmed widespread and abundant established poeciliid populations. The ecological impacts of invasive poeciliids in Africa remain understudied but evidence indicates deleterious effects on native fish, invertebrates, and amphibians, many of which are critically endangered or endemic species. Conclusion. An increased effort to monitor species composition in vulnerable waterbodies, especially in the many African countries where invasive poeciliids are reported should be completed and to reveal further established populations. Future research should prioritise quantifying the ecological impacts of invasive poeciliids in the field and identifying both vulnerable and resistant native ecosystems to guide future management decisions.

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New Record and Biology of the Molly Poecilia sphenops (Poeciliidae), Discovered in the Northern Sahara of Algeria

Cited by 3 publications

References 21 publications

Retinal Structure of Poecilia sphenops: Photoreceptor Mosaics, Synaptic Ribbon Patterns, and Glial Cell Expressions

Retinal Structure of Poecilia sphenops: Photoreceptor Mosaics, Synaptic Ribbon Patterns, and Glial Cell Expressions

Neuron mapping in the Molly fish optic tectum: An emphasis on the adult neurogenesis process

A systematic review of poecilid fish invasions in Africa

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