Species boundaries in Zausodes-complex species (Copepoda:Harpacticoida:Harpacticidae) from the north-eastern Gulf of Mexico

2010 ◽  
Vol 24 (3) ◽  
pp. 258 ◽  
Author(s):  
Erin E. Easton ◽  
David Thistle ◽  
Trisha Spears

Before 1999, the harpacticoid copepod species Zausodes arenicolus Wilson, 1932 was the subject of several ecological studies. Based on morphological evaluations of specimens from the north-eastern Gulf of Mexico, Bouck et al.’s (1999) taxonomic revision revealed three new species within what had been Z. arenicolus, making the ecological results suspect. Because harpacticoid copepods show convergent evolution and morphological stasis, Bouck et al.’s morphologically based approach may not have been sufficient. We have therefore re-evaluated their results using a combination of gene-sequencing and morphological methods. Partial mitochondrial cytochrome b (cytb) and 18S rRNA gene regions from individual Zausodes specimens found at five sites in the north-eastern Gulf of Mexico were separately analysed. Individuals of Zausodes septimus Lang, 1965 formed a single cytb gene-sequence clade, whereas Z. arenicolus individuals formed five. The uncorrected genetic divergences among these clades were 10 times those within them, providing evidence that each clade could be assigned to a different species. The 18S rDNA results support those from cytb. Subsequent morphological analysis revealed differences that will allow two clades of Z. arenicolus to be described as new species. Bouck et al. (1999) revealed some but not all of the species present.

2017 ◽  
Vol 98 (7) ◽  
pp. 1619-1644 ◽  
Author(s):  
Alexandre Dias Pimenta ◽  
Bruno Garcia Andrade ◽  
Ricardo Silva Absalão

A taxonomic revision of the Nystiellidae from Brazil, including samples from the Rio Grande Rise, South Atlantic, was performed based on shell morphology. Five genera and 17 species were recognized. For the richest genus,Eccliseogyra, the three species previously recorded from Brazil were revised:E. brasiliensisandE. maracatu, previously known only from their respective type series, were re-examined. Newly available material ofE. maracatuexpanded the known geographic range of this species to off south-east Brazil.Eccliseogyra nitidais now recorded from north-eastern to south-eastern Brazil, as well as from the Rio Grande Rise. Three species ofEccliseogyraare newly recorded from the South Atlantic:E. monnioti, previously known from the north-eastern Atlantic, occurs off eastern Brazil and on the Rio Grande Rise; its protoconch is described for the first time, confirming its family allocation.Eccliseogyra pyrrhiasoccurs off eastern Brazil and on the Rio Grande Rise, andE. folinioff eastern Brazil. The genusIphitusis newly recorded from the South Atlantic.Iphitus robertsiwas found off northern Brazil, although the shells show some differences from the type material, with less-pronounced spiral keels. Additional new finds showed thatIphitus cancellatusranges from eastern Brazil to the Rio Grande Rise, and Iphitusnotiossp. nov. is restricted to the Rio Grande Rise.Narrimania, previously recorded from Brazil based on dubious records, is confirmed, including the only two living species described for the genus:N. azelotes, previously only known from the type locality in Florida, andN. concinna, previously known from the Mediterranean. A third species,Narrimania raquelaesp. nov. is described from eastern Brazil, diagnosed by its numerous and thinner cancellate sculpture. To the three species ofOpaliopsispreviously known from Brazil, a fourth species,O. arnaldoisp. nov., is added from eastern Brazil, and diagnosed by its very thin spiral sculpture, absence of a varix, and thinner microscopic parallel axial striae.Papuliscala nordestina, originally described from north-east Brazil, is recorded off eastern Brazil and synonymized withP. elongata, a species previously known only from the North Atlantic.


1965 ◽  
Vol 97 (6) ◽  
pp. 561-580 ◽  
Author(s):  
Richard B. Selander

Abstract>Three species are recognized in the North American genus Megetra LeConte. The most distinctive of these anatomically and ecologically is M. cancellata (Brandt and Erichson), which ranges discontinuously from Arizona and New Mexico to the state of Hidalgo in México and occurs in limited sympatry with both of its congeners. Megetra vittata (LeConte) ranges from northern Arizona to western Texas. It appears to be strictly allopatric with, and similar ecologically to, M. punctata, new species, which ranges from southern Arizona and New Mexico to Durango, México. Specific diagnoses are made on the basis of characters of adult and, for M. cancellata and M. punctata, larval anatomy. Intraspecific variation in several adult characters is analyzed. Notes on the seasonal distribution, habitat, and behavior of the adult beetles are included.


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