Observations on courtship,mating and sexual maturity in Portunus pelagicus (L., 1766) (Crustacea,Portunidae)

Summary

Larvae of Alpheus heterochaelis from North Carolina hatch from large eggs as advanced zoeae, usually moult three times, and exhibit almost no linear growth during a short (4 days at 25°c) larval development. Stage I lasts 6 hours at most and is sometimes skipped; III lasts about twice as long as II. Individuals simultaneously exhibiting characteristics of Stage III and the postlarva were occasionally seen. The three zoeal stages and postlarva are described in detail and illustrated. Stages in embryonic and juvenile development and the hatching process are briefly described.

An ‘extended’ pattern of larval development, characteristic of most alpheid species, is described in a general way, and the ‘abbreviated’ development of A. heterochaelis compared to it. At hatching, A. heterochaelis larvae bear rudimentary pereiopods and pleopods; other structures are at the same level of development in both patterns, but subsequent morphogenesis is faster in A. heterochaelis. Larval development of Synalpheus spp., some of which exhibit extreme abbreviation or direct development, is briefly described with reference to the A. heterochaelis pattern.     

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.     

The immature stages of Simulium speculiventre,type-species of Stilboplax Enderlein (Diptera: Simuliidae)

Synopsis

The previously unknown immature stages of Simulium speculiventre are described and figured, and a lectotype is designated for this species from the adult syntypes. S. speculiventre is assigned to the subgenus Eusimulium (new subgeneric combination) and the genus-group name Stilboplax Enderlein is sunk in synonymy with Eusimulium Roubaud (new synonym).     

Larval development and emigration behaviour during sea-to-land transition of the land hermit crab Coenobita brevimanus Dana, 1852 (Crustacea: Decapoda: Anomura: Coenobitidae) under laboratory conditions

To determine the early life history of the land hermit crab Coenobita brevimanus Dana, 1852, larvae were cultured individually in the laboratory. The zoeal and the megalopal stages are described and illustrated. The larvae developed through four planktonic zoeal stages to the megalopal stage. The major differences in the zoeal characters between C. brevimanus and other described Coenobita species were found in the armature of the pleomeres, whereas the character of pleomeres of C. brevimanus zoeae is the same as that of the coconut crab Birgus latro, a different genus in the same family. Morphological similarity was also found in segmentations of antennules and antennae in megalopae between C. brevimanus and the coconut crab. Megalopae of C. brevimanus were cultured in containers holding seawater and a hard substrate. These crabs migrate from the sea to land after developing a habit of acquiring gastropod shells.     

On a collection of Banchinae from Australia (Hymenoptera: Ichneumonidae)

Summary

The first zoeal stage of Ebalia nux Milne Edwards is described and the available information on leucosiid larvae is reviewed. A comparison of the zoeal characters of the Leucosiidae, particularly of the telson and the cephalothoracic appendages, with those of other brachyurans provides no evidence for the inclusion of this family in a distinct oxystomatous group along with the dorippids and calappids. Rather, the leucosiids appear to be highly evolved catometopous crabs, most closely related to the pinnotherids and somewhat less closely to the ocypodids.     

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.     

A new species of Prosimulium Roubaud (Diptera:Simuliidae) from Rhodesia

Summary

A new species of Prosimulium from Rhodesia is described and placed in the damarense-group; this species-group is defined and keys are given for the identification of its three constituent species in larval, pupal and adult stages.     

The Biology and Development of Brachygaster minutus Olivier (Hymenoptera: Evaniidae), a parasite of the oothecae of Ectobius spp. (Dictyoptera: Blattidae).

Summary

Brachygaster minutus is a parasite of the oothecae of three species of British field-dwelling cockroaches belonging to the genus Ectobius. This species has previously received very little attention probably due to its restricted occurrence in Britain and the difficulties encountered in its collection. The life cycle and development of the parasite is described. The species is solitary in habit, the single larva overwintering within the ootheca as a final instar. The emergence of the adult the following summer is perfectly synchronized with the occurrence in the field of the particular cockroach species. Aspects of the mating and oviposition behaviour of the parasite are described.     

Zoeal stages of Hiplyra variegata (Rüppell, 1830) (Crustacea: Brachyura: Leucosiidae) reared in the laboratory and collected from plankton at Al-Kharrar creek,central Red Sea

The zoeal stages of Hiplyra variegata are described and illustrated for the first time. Zoea I was obtained from an ovigerous female, and the zoea II and zoea III stages were captured in the plankton (their identity was confirmed by rearing some of them from earlier stages). Comparisons are made with the only other species of the genus of which larvae are known, i.e. H. platycheir. The presence of a lateral spine on the carapace of zoea I is one of the most important characters that can be used for easy recognition of H. variegata. It is important to note that the third zoea of H. variegata has four small spines at each posterolateral margin of the carapace, in contrast to three spines in other species.     

The complete larval development of Sadayoshia edwardsii (37) (Decapoda: Anomura: Galatheidae) described from laboratory‐reared material

The complete larval development of Sadayoshia edwardsii (Miers, ) is described and illustrated from laboratory‐reared material. The development comprises four zoeal and one megalopal stages. Diagnostic zoeal characters of Sadayoshia are provided and these are compared with other galatheid genera for which the larval morphology is known. Zoeas of S. edwardsii are readily distinguished from those of other galatheid species by the setation of the maxillular endopod together with the basis and endopod of the first maxilliped. The megalop of S. edwardsii has a flattened, triangular‐shaped rostrum, which differs remarkably from that of the adult. Although the rostral shape resembles that of Galathea megalops, the armature of the lateral margins is different between megalops of the two genera. The present larval study suggests that Sadayoshia is more closely allied to Galathea than to Munida.     

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.     

A new species of Lysianassa Milne-Edwards (Amphipoda: Lysianassidae) from the Channel Isles

Summary

A new species of Lysianassa is described from Guernsey, collected by Norman in 1906 and previously identified as L. plumosa Boeck. The new species is readily separated from the two allied species, plumosa and cinghalensis, by the deeply excavate palm of gnathopod 2 and the large tooth on epimeral plate 3, respectively.     

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.