478 research outputs found

    Variación morfológica y un nuevo y remarcable tipo de dimorfismo sexual en la población de Pseudocyclops xiphophorus del Lago Faro en el noreste de Sicilia

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    The population of P. xiphophorus in Lake Faro exhibits variation in the form of caudal seta V. In some specimens of both sexes, this seta is spatulate but in others it is slender and unmodified. Occasional specimens are asymmetrical. In addition to this variation in caudal seta form, the Lake Faro population displays variation in male body length and in the extent of the sexually dimorphic specialisation of the right swimming leg 2. The scale of these differences between the morphotypes might suggest their taxonomic treatment as distinct species. The modification of the distal two segments of the exopod of right leg 2 in the male is a unique sexual dimorphism. We infer, from the presence of this hook on the right exopod in adult males only, that it is involved in mating behaviour. Laboratory-based breeding experiments between females and males showing different combinations of these characters were also performed. Experiments comparing egg production rates in females that have mated with modified or unmodified males revealed no significant differences. It appears therefore that gene flow is not interrupted between the morphotypes and that reproductive segregation does not occur. Observations of male leg 5 morphology and musculature revealed no significant differences between the two P. xiphophorus morphotypes.La población de P. xiphophorus del Lago Faro muestra variación en la forma de la seda caudal V. En algunos especímenes de ambos sexos presenta una morfología espatulada, pero en otros es esbelta y sin modificaciones. Ocasionalmente, es asimétrica en un mismo individuo. La población del Lago Faro muestra también variabilidad en la longitud corporal del macho y en el grado de dimorfismo sexual de la segunda pata natatoria derecha. La escala de estas diferencias entre morfotipos podría sugerir un tratamiento específico diferente para ellos. La modificación en el macho de los dos segmentos distales del exópodo de la segunda pata natatoria derecha es un carácter desconocido en otras especies del género. La presencia de un gancho en el exópodo derecho de los machos sugiere que esta modificación está relacionada con el comportamiento de apareamiento. Se han realizado cruzamientos en laboratorio entre hembras y machos que mostraban diferentes combinaciones de estos caracteres. La comparación de las tasas de producción de huevos en hembras que se han cruzado con machos con o sin modificaciones no muestra diferencias significativas. Parece por tanto que el flujo génico entre morfotipos no está interrumpido y que no tiene lugar segregación reproductiva. La observación de la morfología y del patrón muscular de la pata quinta del macho no ha revelado tampoco diferencias significativas entre los dos morfotipos de P. xiphophorus

    Misophriopsis okinawensis sp. nov. (Crustacea: Copepoda) from Hyperbenthic Waters off Okinawa, South Japan, with Definitions of Related Genera Misophria Boeck, 1864 and Stygomisophria gen. nov.

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    A new misophrioid copepod Misophriopsis okinawensis (Crustacea) is reported from Kume Island, Okinawa, South Japan. A full description of the new misophrioid is presented, together with supplementary notes on the males of Misophria pallida Boeck, 1864. Consideration of the phylogeny of the new species led to a reassessment of the affinities between all the named species of Misophria Boeck, 1864 and Misophriopsis Boxshall, 1983. A new genus, Stygomisophira, is recognised based on Misophria kororiensis Boxshall et Iliffe, 1987. Diagnoses are presented of all three genera

    Two new species of parasitic copepods from the genera Nothobomolochus and Unicolax (Cyclopoida: Bomolochidae) from Australian waters

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    A 2016 collaborative survey of commercial fish parasites in Moreton Bay, Queensland, Australia led to the discovery of two new species of parasitic copepods belonging to the family Bomolochidae. Females of Nothobomolochus johndaveorum n. sp. were found attached to the gill filaments of Gerres subfasciatus and Gerres oyena. The new species most closely resembles N. leiognathicola and N. quadriceros. All 3 species possess 3 modified setae on the first antennulary segment that are approximately the same length and have a robust seta on the second antennulary segment adjacent to the 3 modified setae giving a superficial appearance of 4 modified setae on the antennule. The new species can be distinguished from these two species in its possession of longer inner setae on the first two endopodal segments of leg 4: the seta on endopodal segment 1 extends past the midline of the distal segment in the new species vs to the proximal margin of the distal segment in the other two species, and the seta on segment 2 extends well beyond the distal margin of the endopod in the new species vs just to the margin in the other two species. Females and males of Unicolax longicrus n. sp. were found in the nasal sinuses of Sillago maculata and Sillago ciliata. The new species differs from 6 of its 7 congeners in having a leg 4 exopod formula of II, I, 4 rather than II, I, 3 or II, I, 5. The new species resembles U. anonymous in this feature, but differs in its possession of a leg 5 that is relatively longer and less wide, and, whereas U. anonymous possesses inner and outer distal spines on leg 5 that are approximately the same length, those of the new species are relatively longer and asymmetrical. Unicolax longicrus n. sp. is unique among its congeners in its possession of a leg 4 with highly elongated endopodal segments 2 and 3, from which its name is derived. In addition to describing the two new species, host and locality reports for all species of Nothobomolochus and Unicolax are reviewed

    A New Species of Paramacrochiron (Copepoda: Cyclopoida: Macrochironidae) Associated with the Rhizostome Medusa Rhopilema hispidum Collected from the Gulf of Thailand, with a Phylogenetic Analysis of the Family Macrochironidae

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    Paramacrochiron thailandicum n. sp. (Copepoda: Cyclopoida: Macrochironidae) is described from the rhizostome medusa Rhopilema hispidum occurring in the Gulf of Thailand. The new species is distinguishable from other congeners mainly by detailed features of the fourth legs and the urosome in both sexes. Copepodid and adult stages of the genus Paramacrochiron seem to be host-specific to rhizostome medusae, but may spend periods free in the plankton or benthos during the absence of the host. A cladistic analysis shows that the Macrochironidae comprises two main lineages. Paramacrochiron is recovered as a monophyletic group, located on one lineage together with Pseudomacrochiron, which appears as a paraphyletic taxon with the limited character set used. The other main lineage comprises the genera Macrochiron and Sewellochiron, but the sole species of the latter genus, Sewellochiron fidens, is nested within Macrochiron. This analysis provides little support for maintaining Sewellochiron as a separate genus

    Some Observations of Morphology and Behavior of a Hyperbenthic Misophrioid Copepod

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    The locomotion, feeding, excretion, and oviposition of a member of the copepod family Misophriidae were observed based on a live specimen collected from a sandy bottom at a depth of 52 m off Nagannu Island, Okinawa, Japan. This species is related to Arcticomisophria Martínez Arbizu and Seifried, 1996 in the armature of leg 1, but the fifth leg is much more reduced. The combination of morphological characters strongly suggests that it represents an undescribed genus. The maxillipeds played a major role in attaching to the bottom and in crawling, while the antennae and mandibular palps were involved in slow swimming along the bottom. It fed on small-sized cultured phytoplankters, and excreted numerous fecal pellets. The female carried 4-5 eggs of 0.09 mm diameter that were loosely attached to the urosome. Nearly complete nuclear 18S and 28S rRNA gene sequences and a partial mitochondrial cytochrome c oxidase subunit 1 (CO1) gene sequence were obtained and are made available for future phylogenetic and systematic work

    An evaluation of Sea Search as a citizen science programme in Marine Protected Areas

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    Citizen science involves collaboration between multi-sector agencies and the public to address a natural resource management issue. The Sea Search citizen science programme involves community groups in monitoring and collecting subtidal rocky reef and intertidal rocky shore data in Victorian Marine Protected Areas (MPAs), Australia. In this study we compared volunteer and scientifically collected data and the volunteer motivation for participation in the Sea Search programme. Intertidal rocky shore volunteer-collected data was found to be typically comparable to data collected by scientists for species richness and diversity measures. For subtidal monitoring there was also no significant difference for species richness recorded by scientists and volunteers. However, low statistical power suggest only large changes could be detected due to reduced data replication. Generally volunteers recorded lower species diversity for biological groups compared to scientists, albeit not significant. Species abundance measures for algae species were significantly different between volunteers and scientists. These results suggest difficulty in identification and abundance measurements by volunteers and the need for additional training requirements necessary for surveying algae assemblages. The subtidal monitoring results also highlight the difficulties of collecting data in exposed rocky reef habitats with weather conditions and volunteer diver availability constraining sampling effort. The prime motivation for volunteer participation in Sea Search was to assist with scientific research followed closely by wanting to work close to nature. This study revealed two important themes for volunteer engagement in Sea Search: 1) volunteer training and participation and, 2) usability of volunteer collected data for MPA managers. Volunteer-collected data through the Sea Search citizen science programme has the potential to provide useable data to assist in informed management practices of Victoria&rsquo;s MPAs, but requires the support and commitment from all partners involved.<br /

    Parasitic copepods from Egyptian Red Sea fishes: Bomolochidae Claus, 1875

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    © The Author(s) 2015 Open Access - This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The attached file is the published version of the article

    Historical biogeography of the neotropical Diaptomidae (Crustacea:Copepoda)

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    Introduction: Diaptomid copepods are prevalent throughout continental waters of the Neotropics, yet little is\ud known about their biogeography. In this study we investigate the main biogeographical patterns among the\ud neotropical freshwater diaptomid copepods using Parsimony Analysis of Endemicity (PAE) based on species records\ud within ecoregions. In addition, we assess potential environmental correlates and limits for species richness.\ud Results: PAE was efficient in identifying general areas of endemism. Moreover, only ecoregion area showed a\ud significant correlation with diaptomid species richness, although climatic factors were shown to provide possible\ud upper limits to the species richness in a given ecoregion.\ud Conclusion: The main patterns of endemism in neotropical freshwater diaptomid copepods are highly congruent\ud with other freshwater taxa, suggesting a strong historical signal in determining the distribution of the family in the\ud Neotropics.We would like to thank to Professor Edinaldo Nelson dos Santos Silva (INPA, Brazil) for useful insight during this study. We also thank FAPESP (process 2008/02015-7, 2009/00014-6, 2011/18358-3) for financial support to GPN; and CNPq for financial support to DP (process 141702/2006-0) and MRP (process 304897/2012-4)
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