Contenido bioquímico del ovario y hepatopáncreas de Uca longisignalis y Uca nr. minax

P align=justify>Biochemical composition of ovary and hepatopancreas tissues in wild populations of Uca longisignalis and Uca nr. minax were monitored during the reproductive season. Total lipid (concentration and content), C (carbon), N (nitrogen), and C:N ratios of the ovary and hepatopancreas were quantified over the course of ovarian maturation. Ovary lipid and C concentration varied significantly over the course of ovarian maturation for both species, but there was no relationship between lipid concentration or hepatopancreas content and the stage of ovarian development in females. Hepatopancreatic lipid and C concentration did not differ between sexes of U. nr. minax. Lipid demands of ovarian maturation thus appear to be met in large part by increased dietary intake and not purely by translocating lipid stores from the hepatopancreas. In both Uca longisignalis and U. nr. minax, the color of the hepatopancreas may be used as an indicator of the lipid and C levels of the hepatopancreas. Cadmium-yellow and lemon-yellow hepatopancreas tissues had the highest lipid concentrations. No evidence could be found to demonstrate depletion of lipid or C concentrations in the hepatopancreas concomitant with ovarian maturation. Se analizó la composición bioquímica de tejidos del ovario y hepatopáncreas de poblaciones naturales de Uca longisignalis and Uca nr. minax durante la época reproductiva. Se cuantificaron lípidos totales (concentración y contenido), C (carbono), N (nitrógeno), y los cocientes C:N del ovario y hepatopáncreas durante el proceso de maduración del ovario. Los lípidos y la concentración de C variaron significativamente durante el curso de maduración del ovario en ambas especies, pero no se encontró ninguna relación entre la concentración o contenido de lípidos del hepatopáncreas con el estadío de desarrollo del ovario en hembras. Tampoco se encontró ninguna diferencia en los lípidos del hepatopáncreas y la concentración de C entre sexos de la especie Uca nr. minax. La demanda de lípidos durante la maduración del ovario, parece ser aportada en gran parte por un incremento en la dieta diaria y no solamente por la translocación de reservas de lípidos desde el hepatopáncreas. En ambas especies, Uca longisignalis y U. nr. minax, el color del hepatopáncreas puede ser usado como un indicador de los niveles de lípidos y C en el hepatopáncreas. Los tejidos del hepatopáncreas con color amarillo-cadmio y amarillo-limón tuvieron las más altas concentraciones de lípidos. No se encontró ningúna evidencia para demostrar que la disminución en la concentración de lípidos y C en el hepatopáncreas es concomitante con la maduración del óvulo.

Phylogenetics links monster larva to deep-sea shrimp.

Mid-water plankton collections commonly include bizarre and mysterious developmental stages that differ conspicuously from their adult counterparts in morphology and habitat. Unaware of the existence of planktonic larval stages, early zoologists often misidentified these unique morphologies as independent adult lineages. Many such mistakes have since been corrected by collecting larvae, raising them in the lab, and identifying the adult forms. However, challenges arise when the larva is remarkably rare in nature and relatively inaccessible due to its changing habitats over the course of ontogeny. The mid-water marine species Cerataspis monstrosa (Gray 1828) is an armored crustacean larva whose adult identity has remained a mystery for over 180 years. Our phylogenetic analyses, based in part on recent collections from the Gulf of Mexico, provide definitive evidence that the rare, yet broadly distributed larva, C. monstrosa, is an early developmental stage of the globally distributed deepwater aristeid shrimp, Plesiopenaeus armatus. Divergence estimates and phylogenetic relationships across five genes confirm the larva and adult are the same species. Our work demonstrates the diagnostic power of molecular systematics in instances where larval rearing seldom succeeds and morphology and habitat are not indicative of identity. Larval-adult linkages not only aid in our understanding of biodiversity, they provide insights into the life history, distribution, and ecology of an organism

Redescription of Pinnixa arenicola Rathbun, 1922 (Decapoda: Brachyura: Pinnotheridae), with new observations on its range and host

Abstract.-Pinnixa arenicola is redescribed and illustrated on the basis of new collections and reexamined type material. Its occurrence in the burrows of Upogebia vasquezi Ngoc-Ho is reported, along with range extensions that include Florida, Puerto Rico, Aruba, and the Cayman Islands. New collections represent the first reports of P. arenicola since original discoveries in Curaçao and suggest a potentially wide distribution of the species in the tropical western Atlantic. Following publication of the unillustrated original description for the holotype male, females were also noted to occur in Curaçao, but illustrations with limited detail were provided by Rathbun for only the male holotype specimen. Prior to our work, no illustrations have depicted female morphology, unique male gonopods, or some pereopod features of potential value in defining phylogenetic relationships

Transcriptomic effects of dispersed oil in a non-model decapod crustacean

Background. Oil spills are major environmental disasters. Dispersants help control spills, as they emulsify oil into droplets to speed bioremediation. Although dispersant toxicity is controversial, the genetic consequences and damages of dispersed oil exposure are poorly understood. We used RNA-seq to measure gene expression of flatback mudcrabs (Eurypanopeus depressus, Decapoda, Brachyura, Panopeidae) exposed to dispersed oil. Methods. Our experimental design included two control types, oil-only, and oil-dispersant treatments with three replicates each. We prepared 100 base pair-ended libraries from total RNA and sequenced them in one Illumina HiSeq2000 lane. We assembled a reference transcriptome with all replicates per treatment, assessed quality with novel metrics, identified transcripts, and quantified gene expression with open source software. Results. Our mudcrab transcriptome included 500,008 transcripts from 347,082,962 pairend raw reads. In oil-only treatments, we found few significant differences. However, in oildispersant treatments, over 4000 genes involved with cellular differentiation, primordial cellular component upkeep, apoptosis, and immune response were downregulated. A few muscle structure and development genes were upregulated. Discussion. Our results provide evidence that exposure to chemically dispersed oil causes a generalized cellular shutdown and muscular repair attempts. Our results suggest current oil-spill treatment procedures could be detrimental to crustaceans and indicate additional research is needed to evaluate the impact of oil spills in gene expression. Finally, traditional quality metrics such as N50s have limitations to explain the nature of RNA-seq compared to new methods in non-model decapod crustaceans

Phylogeny of Stenopodidea (Crustacea: Decapoda) shrimps inferred from nuclear and mitochondrial genes reveals non-monophyly of the families Spongicolidae and Stenopididae, and most of their composite genera

The infraorder Stenopodidea is a relatively small group of marine decapod crustaceans including the well known cleaner shrimps, but their higher taxonomy has been rather controversial. This study provides the most comprehensive molecular phylogenetic analyses of Stenopodidea using sequence data from two mitochondrial (16S and 12S rRNA) and two nuclear (histone H3 and sodium–potassium ATPase α-subunit (NaK)) genes. We included all 12 nominal genera from the three stenopodidean families in order to test the proposed evolutionary hypothesis and taxonomic scheme of the group. The inferred phylogeny did not support the familial ranking of Macromaxillocarididae and rejected the reciprocal monophyly of Spongicolidae and Stenopididae. The genera Stenopus, Richardina, Spongiocaris, Odontozona, Spongicola and Spongicoloides are showed to be poly- or paraphyletic, with monophyly of only the latter three genera strongly rejected in the analysis. The present results only strongly support the monophyly of Microprosthema and suggest that Paraspongiola should be synonymised with Spongicola. The three remaining genera, Engystenopus, Juxtastenopus and Globospongicola, may need to be expanded to include species from other genera if their statuses are maintained. All findings suggest that the morphological characters currently adopted to define genera are mostly invalid and substantial taxonomic revisions are required. As the intergeneric relationships were largely unresolved in the present attempt, the hypothesis of evolution of deep-sea sponge-associated taxa from shallow-water free-living species could not be verified here. The present molecular phylogeny, nevertheless, provides some support that stenopoididean shrimps colonised the deep sea in multiple circumstances

A comprehensive and integrative reconstruction of evolutionary history for Anomura (Crustacea: Decapoda).

BACKGROUND: The infraorder Anomura has long captivated the attention of evolutionary biologists due to its impressive morphological diversity and ecological adaptations. To date, 2500 extant species have been described but phylogenetic relationships at high taxonomic levels remain unresolved. Here, we reconstruct the evolutionary history-phylogeny, divergence times, character evolution and diversification-of this speciose clade. For this purpose, we sequenced two mitochondrial (16S and 12S) and three nuclear (H3, 18S and 28S) markers for 19 of the 20 extant families, using traditional Sanger and next-generation 454 sequencing methods. Molecular data were combined with 156 morphological characters in order to estimate the largest anomuran phylogeny to date. The anomuran fossil record allowed us to incorporate 31 fossils for divergence time analyses. RESULTS: Our best phylogenetic hypothesis (morphological + molecular data) supports most anomuran superfamilies and families as monophyletic. However, three families and eleven genera are recovered as para- and polyphyletic. Divergence time analysis dates the origin of Anomura to the Late Permian ~259 (224-296) MYA with many of the present day families radiating during the Jurassic and Early Cretaceous. Ancestral state reconstruction suggests that carcinization occurred independently 3 times within the group. The invasion of freshwater and terrestrial environments both occurred between the Late Cretaceous and Tertiary. Diversification analyses found the speciation rate to be low across Anomura, and we identify 2 major changes in the tempo of diversification; the most significant at the base of a clade that includes the squat-lobster family Chirostylidae. CONCLUSIONS: Our findings are compared against current classifications and previous hypotheses of anomuran relationships. Many families and genera appear to be poly- or paraphyletic suggesting a need for further taxonomic revisions at these levels. A divergence time analysis provides key insights into the origins of major lineages and events and the timing of morphological (body form) and ecological (habitat) transitions. Living anomuran biodiversity is the product of 2 major changes in the tempo of diversification; our initial insights suggest that the acquisition of a crab-like form did not act as a key innovation

OSMOTIC AND IONIC REGULATION IN SEVERAL WESTERN ATLANTIC CALLIANASSIDAE (CRUSTACEA, DECAPODA, THALASSINIDEA)

Volume: 154Start Page: 409End Page: 42

A new crab of the genus Nanoplax from the Gulf of Mexico, and assignment of Micropanope pusilla to a new genus (Crustacea, Brachyura, Pseudorhombilidae)

Felder, Darryl L. (2020): A new crab of the genus Nanoplax from the Gulf of Mexico, and assignment of Micropanope pusilla to a new genus (Crustacea, Brachyura, Pseudorhombilidae). Zootaxa 4810 (3): 531-545, DOI: https://doi.org/10.11646/zootaxa.4810.3.

A new species of the ghost shrimp genus Lepidophthalmus (Crustacea: Decapoda: Axiidea) from the southwestern Gulf of Mexico

Felder, Darryl L. (2015): A new species of the ghost shrimp genus Lepidophthalmus (Crustacea: Decapoda: Axiidea) from the southwestern Gulf of Mexico. Zootaxa 3985 (3): 409-420, DOI: http://dx.doi.org/10.11646/zootaxa.3985.3.