Mating behaviour,nympho-imaginal development and description of a new Mesabolivar species (Araneae: Pholcidae) from the Brazilian dry forest

A new species of Mesabolivar is described from Brazilian forests: Mesabolivar delclaroi. The mating behaviour, postembryonic development, number of egg sacs and eggs, birth rate, number of instars, developmental time until adulthood, sex ratio and size of cephalothorax (per instar) were recorded. The sexual behaviour was described and categorized into four steps: courtship, pre-copulation, copulation and post-copulation. After hatching, individuals presented five instars until maturity. The mean number of eggs (42 ± 16.6) and live births (31.5 ± 3.4) of the first egg sac were significantly greater than that of a second one (23.8 ± 3.8, and 19.25 ± 3.9, respectively). The developmental time from birth to adulthood (130.8 ± 9.6 days) did not differ significantly between egg sacs produced (128.61 ± 11.1). The size of the cephalothorax did not differ among adults or between sexes. The sex ratio revealed a shift in favour of females (4: 3).     

A taxonomic revision of the genus Ocyale Audouin, 1826 in Africa (Araneae: Lycosidae)

The taxonomy of the African representatives of the wolf spider genus Ocyale is revised. Fundamental taxonomic problems were encountered which resulted in confusion in the literature between Ocyale and Pisaura and thus potential instability of the type genus of the family Pisauridae. For reasons of taxonomic stability, a new type species for Ocyale is proposed here: O. neatalanta. Besides the type species, O. dewinterae n.sp., O. discrepans Roewer, 1960, O. grandis n.sp. and Ocyale guttata Karsch, 1878, are described and an identification key is provided. Ocyale spissa (Lenz, 1895) proved to be a junior synonym of O. guttata. Ocyale maculata (L. Koch, 1875), O. spissides Strand, 1907, O. fera Strand, 1908, O. ingenua (Karsch, 1879) and O. conspersa Karsch, 1879, were found to be either nomina dubia or incertae sedis.     

Abbreviated larval development of the freshwater prawn,Macrobrachium pilimanus (De Man, 1879) (Decapoda,Palaemonidae), reared in the laboratory

The larvae of the freshwater prawn, Macrobrachium pilimanus (De Man, 1879), were reared in the laboratory. Larval development was highly abbreviated, with two zoeal and one megalopal stages. Newly hatched larvae were benthic, with a tendency to cling on to roughened surfaces. All larval stages subsisted solely on endogenous yolk. Morphological and behavioural differences between the first zoea of this species and that of M. malayanum (Roux, 1934) are highlighted. The potential use of larval characters in taxonomy is also discussed.     

The larval development of Petalomera japonica (Henderson) (Decapoda,Dromiidae) reared in the laboratory

The complete larval development of Petalomera japonica (Henderson) is described, based on laboratory rearing. The species has two zoeal stages and a megalopa. Detailed comparisons are made with other dromiid larvae, particularly those of Petalomera wilsoni.     

Larval development of Maja crispata Risso 1827 (Crustacea,Decapoda, Majidae) reared in the laboratory

The morphology of the zoea and megalop of Maja crispata are described from laboratory-reared material, and compared with other two spider crabs belonging to the subfamily Majinae, Maja squinado and Maja goltziana, recorded in the same region of the eastern Atlantic. The diagnostic characters allowing the separation of these species' larvae are tabulated and discussed.     

Larval development of the fiddler shrimp,Metapenaeopsis stridulans (Alcock, 1905) (Decapoda: Penaeidae) reared in the laboratory

Larvae of Metapenaeopsis stridulans (Alcock, 1905) from Malaysia were successfully reared in the laboratory from the egg to the 1st post-larval stage. The larvae developed through six naupliar, three protozoeal and four mysis stages. The morphology of all these larval stages is described and figured.     

Complete larval development of the rare porcellanid crab,Novorostrum decorocrus Osawa, 1998 (Crustacea: Decapoda: Anomura: Porcellanidae), reared under laboratory conditions

The complete larval development of Novorostrum decorocrus Osawa, , is described and illustrated on the basis of laboratory‐reared material. Two zoeal stages and one megalop stage were recorded. Zoeas of N. decorocrus closely resemble those of N. indicum in the appendage characters, including the endopod of the maxillule with only a single stout seta on the distal margin. This character is unique to Novorostrum zoeas. However, N. decorocrus is distinguished from N. indicum by the setation on the endopod of the maxilla and the basis of the second maxilliped in both zoeal stages. The megalops of N. decorocrus are characterized by having a strongly elongate carapace, and differs considerably from the adults in the structure of the carapace, rostrum and third thoracic sternite, and in the armature of the pereiopods. The larval duration of N. decorocrus suggests that this rare porcellanid is more widely distributed than currently known.     

Larval development of Pandalus gracilis Stimpson (Crustacea: Decapoda: Pandalidae) reared in the laboratory

The complete larval development of Pandalus gracilis Stimpson is described based on larvae reared in the laboratory. The species has four larval stages (stages 1–4) and one postlarval stage (stage 5). The survival rate of the postlarva stage is very high. Of the 40 larvae reared individually, 39 larvae moulted to the postlarva stage within approximately 21 days at a rearing temperature of 15°C. Larval morphological characteristics of the species are described and figured. Larval development of P. gracilis is compared with other Pandalus and Pandalopsis species. Komai (1999 Komai, T. 1999. A revision of the genus Pandalus (Crustacea: Decapoda: Caridea: Pandalidae).. Journal of Natural History, 33: 1256–1372.  [Google Scholar]) divided species of Pandalus into four species groups based on adult morphology. Pandalus gracilis belongs to the P. hypsinotus group. In this study, using larval characters, the P. hypsinotus group can be divided into two groups by the appearance of the mandibular palp and the shape of the telson: the first group contains P. hypsinotus and P. danae, and the second group contains P. gracilis, P. prensor, and P. nipponensis.     

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.     

Larval development in Phimochirus roseus (Benedict) (Decapoda: Anomura: Paguridae) reared in the laboratory

The zoeal and megalopal stages of Phimochirus roseus (Benedict, 1892) are described and illustrated from material reared under laboratory conditions. Although the vast majority of zoeae of this species pass through only four larval stages before the moult to megalopa, an occasional fifth stage has been observed. Phimochirus roseus differs in a number of morphological attributes from the only other species of Phimochirus whose larvae have been described. However, their shared features are sufficiently characteristic to confirm the distinctiveness of the genus and its general developmental homogeneity.     

Zoeal development of Ethusa microphthalma smith, 1881 (Brachyura,Dorippidae) reared in the laboratory,with a comparison of other dorippid zoeae

The complete zoeal development of a dorippid crab in the subfamily Ethusinae is described for the first time from a known parental female. The ovigerous Ethusa microphthalma was collected in the northern Gulf of Mexico off Louisiana. Larvae passed through four zoeal stages, and the megalopa was reached in 59 days at 20°C and 35 ppt salinity. The larvae differ from those of the few other dorippids for which a zoea is known. Salient distinguishing features include long lateral carapace spines, the presence of six setae on the endopod of the maxillule and maxilla, and a spinose antennal exopod lacking projecting mid-length spines or setae. Zoeal characters are compared to those known for the allied subfamily Dorippinae, and all references to zoeae of the Dorippidae are tabulated.     

The complete larval development of the Mangrove Ocypodid crab Macrophthalmus depressus Ruppell, 1830 (Brachyura: Macrophthalminae) reared in the laboratory

Macrophthalmus depressus larvae were reared in the laboratory using filtered estuarine water of salinity 25±1 ppt and temperature 29–31°C. M. depressus reaches the first crab stage after passing through five zoeal and a megalopa stage requiring 22–23 days. Each stage is described in detail and compared with other known species of the genus.     

The structure,possible function and origin of the remarkable ladder-web built by a New Guinea orb-web spider (Araneae: Araneidae)

Summary

The remarkable, perpendicularly-elongate web of a New Guinea araneid spider is described and illustrated. Its siting and construction are described and the possible origins and functions of the structure are discussed.     

The complete larval development of the crab Pilumnus spinifer (Brachyura: Xanthoidea: Pilumnidae) reared in the laboratory

The complete larval development of the crab Pilumnus spinifer from the western Mediterranean was obtained in the laboratory. All four zoeal stages and the megalopa are described and illustrated. The morphological characters of the larvae of Pilumnus spinifer are compared with those of other known larvae of the genus. The zoeae of P. spinifer show the rostral spine longer than the antennule (excluding aesthetascs); short lateral spines present on the carapace, and the mediolateral processes are present only in abdominal somites 2 and 3. The megalopa is similar to that of other Pilumnidae species. The morphology of the larval stages shows very similar characteristics to that of those of P. hirtellus and P. dasypodus, among the described stages of the family.     

The larval development of the mud shrimp Upogebia yokoyai Makarov, 1938 (Decapoda: Gebiidea: Upogebiidae) reared under laboratory conditions

Larval development of the mud shrimp Upogebia yokoyai Makarov, 1938 Makarov, VV. 1938. Crustacea Anomura. Fauna USSR. 10;3, Moscow, Leningrad: AN SSSR.  [Google Scholar] (Decapoda: Gebiidea: Upogebiidae) is described and illustrated for the first time from material reared in the laboratory. The development includes four zoeal stages and a megalopa. At 20–22°C the megalopa was attained 16 days after hatching. The zoeae of U. yokoyai are distinguishable from those of the sympatric species Upogebia major and Upogebia issaeffi, inhabiting Russian waters of the Sea of Japan, by the presence of two pairs of spines (posterolateral and posterodorsal), each on the fourth and fifth pleonal somites. The megalopa of U. yokoyai differs in the length of the rostral spine, shape of telson and number of antennular aesthetascs.     

Juvenile development and growth patterns in the mud crab Eurytium limosum (Say, 1818) (Decapoda,Brachyura, Xanthidae) under laboratory conditions

The post‐larval development of the mud crab Eurytium limosum was studied under laboratory conditions by using the offspring of ovigerous females collected at the Comprido River mangrove, SP, Brazil. The first crab stage is fully described and the juvenile development, until crab stage 10, is examined with emphasis on morphological change, sexual differentiation and growth patterns. The carapace of the first crab stage is nearly square as observed in other xanthids, becoming similar to adults only at stage 15. The sexes can be distinguished from stage four, based on the number of pleopods and their morphology. While the intermoult period increases, the moult percentage decreases at each stage. The abdominal allometric growth is sex‐dependent, with males showing a negative (b?=?0.71) and females an isometric (b?=?0.95) relative growth pattern. Male gonopods undergo a positive allometric growth, and their shape changes remarkably until sexual maturity. The cheliped dentition can be observed after stage 4. Regardless of sex, most crabs have a molariform right cheliped, which is thought to aid the handling of asymmetric prey such as gastropods.     

The larval and post-larval development of Gibbs's spider crab,Pisa armata (Latreille) [family Majidae: subfamily Pisinae], reared in the laboratory

Summary

The larvae and first crab stage of the spider crab Pisa armata are described from laboratory reared material. The larval stages are compared with previous accounts and with those of Pisa tetraodon. Larval affinities with other genera of Pisinae are discussed.