New Sandhoppers (Crustacea: Amphipoda) from the Gulf Coast of the United States

Three species of sand-burrowing semi-terrestrial amphipod crustaceans are newly described from sandy beaches of the North American coast of the Gulf of Mexico. They (and two related species from the open Atlantic coast of North America) are removed from the genus Talorchestia Dana 1853, and placed in a new genus, Americorchestia. Americorchestia salomani, new species, and A. heardi, new species, occur from northwestern Florida to the Mississippi Delta. They are morphological counterparts of the well-known sandhoppers from the open Atlantic coast, A. megalophthalma (Bate) and A. longicornis (Say) respectively. Americorchestia barbarae, new species, related to A. salomani, occurs on open beaches west of the Mississippi Delta. Sandhopper species of the Gulf coast are smaller, have different food resources available to them, and are exposed to different physical and biological survival factors than their counterparts from the North Atlantic coastal regio

A new genus and species of Ladzioidean amphipod crustacean from anchialine pools in Hawaii

Carnarimelita janstocki, new genus, new species, a large predatory melitid amphipod (Gammaridea: Hadzioidea), is described from anchialine pools on the island of Hawaii

Características morfométricas de Talitroides topitotum (Burt) (Crustacea, Amphipoda, Talitridae) na Serra do Mar, Guaratuba, Paraná, Brasil Morphometric characteristics of Talitroides topitotum (Burt) (Crustacea, Amphipoda, Talitridae) from Serra do Mar, Guaratuba, Paraná, Brazil

Um estudo sobre as relações morfométricas entre o comprimento cefálico (Lc) e o comprimento total do corpo (Lt), e o número de artículos do flagelo do primeiro e segundo pares de antenas e o comprimento total do corpo foi realizado em uma população de Talitroides topitotum (Burt, 1934), no entorno da Usina Hidroelétrica de Guaricana, Guaratuba, Paraná. O objetivo foi auxiliar na inferência do comprimento do corpo a partir do comprimento cefálico e da idade relativa dos exemplares pela contagem do número de artículos de seus flagelos antenais. Um total de 975 exemplares foi coletado e fotografado, dos quais os artículos dos flagelos direito e esquerdo das antenas 1 e 2 foram contados e os comprimentos do segmento cefálico e do corpo foram medidos. Houve uma correlação linear entre o comprimento do segmento cefálico e o comprimento total do corpo definido pela equação Lc = 0,0506Lt + 0,3297; r² = 0,9577. Diferenças significativas foram observadas entre os números de artículos dos flagelos direito e esquerdo de ambas as antenas. A diferença foi de até quatro artículos no primeiro par de antenas e de doze no segundo. O maior número de artículos entre os dois flagelos mostrou uma correlação com a distribuição das classes de comprimento total do corpo com a equação a1 = 4,3463Lt0,4264 para o primeiro par de antenas, e a2 = 10,5700Lt0,3581 para o segundo par. Foi possível inferir o estágio relativo de desenvolvimento de T. topitotum pelas medidas do comprimento do segmento cefálico. Entretanto, somente o maior número de artículos entre os flagelos direito e esquerdo constitui parâmetro de referência para inferir a idade relativa dos indivíduos desta espécie.<br>A research on the relationship between the cephalic segment length (Lc) and total body length (Lt), and between the number of articles in the antenna flagellum and the total body length was conducted in a population of the terrestrial amphipod Talitroides topitotum (Burt, 1934) from Serra do Mar, Guaratuba, Paraná. It aimed to help the inference of the body length by measuring only the cephalic segment, and to know the relative age of individuals by counting the number of articles in their antenna flagellum. A total of 975 amphipods were caught with Malaise nets; they were photographed, the article number of the flagellum of the right and left antennae 1 and 2 was counted and cephalic segment length and their total body length was taken. There was a linear correlation between cephalic segment length and total body length defined through the equation Lc = 0.0506Lt + 0.3297; r² = 0.9577. There was a significant difference in the article number between the right and left flagellum, for both pairs of antennae. The difference was at most four articles for the fist antenna pair and twelve articles for the second one. The highest number of these articles between right and left flagellum showed a linear correlation with the total body length classes and it was expressed by the equation a1 = 4.3463Lt0.4264 for the first pair of antenna, and a2 = 10.5700Lt0.3581 for the second pair. I was possible to infer the relative stage of development of T. topitotum by measuring the cephalic segment length. However, only the highest number of articles between right and left flagellum constitutes a reference parameter for the inference of individual relative age in this species