New xenophyophores (Protista) from the bathyal and abyssal north-east Atlantic Ocean

Eight species of xenophyophores, seven of them new, are described from epibenthic sledge material collected in the north-east Atlantic by the Institute of Oceanographic Sciences. A new genus is established for two of the new species, Homogammina lamina and H. maculosa. The other five new species are Galatheammina discoveryi, G. microconcha, Psammina delicata, P. fusca and P. sabulosa. The eighth species is Reticulammina labyrinthica Tendal, 1972, first described from the south-west Pacific. The material considerably expands knowledge of north-east Atlantic xenophyophores, emphasizes the dominance in this area of the order Psamminida, and suggests a considerable degree of endemism. All specimens are highly fragmented and it is therefore difficult to correlate the species described from the samples with those appearing in simultaneously taken bottom photographs.     

Larval development of the circular crab,Atelecyclus rotundatus (Olivi) (Crustacea: Brachyura: Atelecyclidae) reared in the laboratory

The complete larval development is described of laboratory-reared Atelecyclus rotundatus and the stages are compared with larvae of other cancrideans (= corystoideans). The results suggest that the subfamily Atelecyclinae requires reappraising and that present larval evidence does not support the currently accepted grouping of families in the Cancridea.     

A new species of Valettia (Crustacea: Amphipoda) and the relationship of the Valettidae to the Lysianassoidea

The family Vallettidae is re-established to accommodate Valettia coheres Stebbing, 1888 and V. hystrix sp. nov. Although closer to the Lysianassoidea than to any other gammaridean superfamily, characters of the mandible, maxillae, gnathopods and oostegites preclude membership of that superfamily. Further assessments of the Valettidae and other family groups peripheral to the Lysianassoidea will be required before formal high-level classification can be established.     

Parasitic copepods of Carcharhinidae and Sphyridae (Elasmobranchia) from the Atlantic Ocean

Seventy-four sharks of the families Carcharhinidae and Sphyridae, mainly from the central Atlantic Ocean, were examined. Fourteen species of Copepoda were found on them. Prionace glauca and Sphyrna zygaena are new hosts for the copepod Pandarus floridanus. Kroyeria carchariaeglauci is reported from the nasal cavities of Prionace glauca for the first time.     

Little-known Atlantic Cheilostome Bryozoans at the entrance to the Mediterranean

Seven little-known Atlantic species of Bryozoa have been found in the Straits of Gibraltar and are re-described in this paper. For six species their known geographical ranges are significantly increased. They are illustrated by SEM for the first time. New ecological and anatomical data are included. Escharella hexaespinosa Arístegui, 1984 is considered to be a junior synonym of Escharella praealta (Calvet, 1907), n. comb.     

Apodidymochelia,a new genus of gammaridean amphipod from the tropical Atlantic Ocean (Crustacea: Amphipoda: Didymochellidae)

Apodidymochelia castellata, new genus, new species is the second genus and fourth species in the rare and poorly known family Didymocheliidae. Apodidymochelia is separated from Didymochelia primarily on mandible structure. This record extends the known range of the family into the Atlantic Ocean.     

Fluctuating asymmetry in populations of the South American frog Physalaemus cuvieri (Leptodactylidae) in areas with different degrees of disturbance

Methods to measure and monitor wild populations are important conservation tools in areas affected by anthropogenic disturbances. We compared three populations of the South American frog Physalaemus cuvieri Fitzinger, 1826 (Leptodactylidae) from areas with different degrees of anthropogenic disturbance in regard to their degrees of fluctuating asymmetry (FA). We selected four morphological characters (radio-ulna, femur, tibia-fibula and digit length) and compared two populations from relatively pristine areas with one population located in a highly urbanised and disturbed area. We found a significantly higher level of FA for the digit length, p < 0.05, in the population suffering the highest level of anthropogenic disturbance in relation to the two populations located in the pristine areas. There are no significant differences in the three populations in regard to FA for the radio-ulna, femur and tibia-fibula. The absence of FA in these three measurements might indicate a negative effect of limb asymmetry on this species survivorship. Our study provides a good example of the use of FA as indicator of environmental stress. However, this result must be viewed with some caution, since we observed FA in only one morphological character.     

On some Maerid genera (Crustacea,Amphipoda, Maeridae) collected by the Hourglass Cruises (Florida). Part 1: Genera Anamaera,Ceradocus, Clessidra gen. nov., Jerbarnia,Maera, Meximaera,with a key to world Ceradocus

This paper deals with some of the Amphipoda Maeridae, i.e. seven species in the genera Anamaera, Ceradocus, Clessidra gen. nov., Jerbarnia, Maera and Meximaera, collected during the Hourglass cruises, a 28-month sampling programme at 10 stations (5–73 m depth) on the central West Florida shelf. A new genus Clessidra is erected for Maera tinkerensis Kunkel, and Maera caroliniana Bynum and Fox is found to be a junior synonym of Meximaera diffidentia. Keys to these Atlantic maerids, and to world Ceradocus species, are provided.     

On the South American species of the genus Meridiosignum (Crustacea: Isopoda: Asellota: Paramunnidae)

Meridiosignum undulatum n. sp. and M. disparitergum n. sp. are described from off the Río de la Plata estuary. These two new species are easily distinguished from other members of the genus Meridiosignum in having the lateral margins of pereonites 2 and 3 bilobed (the concavity is much more pronounced in M. disparitergum), and those of pereonite 4 produced into a single process. The terminal male instar of Meridiosignum menziesi (Winkler, 1994 Winkler, H. 1994. Paramunnidae (Crustacea: Isopoda: Asellota) from the Magellan Strait.. Zool J Linn Soc., 110: 243–296. [Crossref] , [Google Scholar]) is described, and this species is herein reported from the Beagle Channel and Puerto Deseado. All the species currently placed in Meridiosignum were found in shallow waters in the southern hemisphere, M. undulatum n. sp. and M. disparitergum n. sp. being the species recorded at the greatest depth (129 m).