The developmental sequence of Argulus foliaceus (Crustacea: Branchiura)

We describe and illustrate the complete development of Argulus foliaceus L. A metanauplius is followed by nine juvenile stages. Eggs were detected in the thorax of the female at the 11th stage. Comparisons are made between the development of A. foliaceus and the other freshwater species of Argulus currently found in the UK.     

Morphology of abdominal evaporatoria in larvae of some Lygaeoidea (Insecta: Hemiptera: Heteroptera): function and bearing on classification

The dorsal abdominal scent glands of nymphs in Lygaeoidea are diverse. Some related characters, such as number and distribution of dorsal abdominal scent gland openings (DSOs), and shapes of dark plates surrounding DSOs have been commonly used in taxonomic and/or phylogenetic studies of Lygaeoidea. However, comparative studies of the cuticular fine structures surrounding the DSOs in lygaeoid (and other Heteroptera) nymphs are few. We examined the cuticular fine structures surrounding DSOs of fifth‐instar nymphs of 25 species in seven families of Lygaeoidea with scanning electron microscopy. The results showed that the structures surrounding DSOs, such as distribution pattern of cell network, type of network, type of non‐latticed area, pattern of channels for glandular secretion, are complicated and diverse at the family level, indicating that they are valuable in taxonomic and phylogenetic analyses.     

The larval development of the spider crab Rochinia gracilipes (Crustacea: Majoidea: Epialtidae: Pisinae) reared in the laboratory

The larval development of the spider crab Rochinia gracilipes Milne-Edwards, 1875 (Crustacea: Decapoda: Brachyura: Majoidea: Epialtidae: Pisinae) is described and illustrated from laboratory-reared larvae. Development consisted of two zoeal stages and one megalopa, following the typical pattern in Majoidea. Zoea I of R. gracilipes, R. debilis and R. carpenteri differed in lengths of the rostral spine of the carapace, in the number of setae and aesthetascs of several head appendages (exopods of antennules, endopods of maxillules, and endopods and scaphognathites of maxillae) and in the length of posterolateral processes of abdominal somites; lateral carapace spines were present only in R. carpenteri and pleopod buds only in R. debilis. Megalopae of Rochinia gracilipes and R. carpenteri differed in several notable characters: a dorsal spine and long rostrum of the carapace, as well as spines in coxa and ischium of pereiopods, appeared only in R. carpenteri, and podobranchiae of the 3rd maxilliped appeared only in R. gracilipes; they also differed in setation of abdomen and pleopods. The comparison of the available information on Pisinae larval development suggested that larval morphology would not help to accurately understand the phylogenetic relationships of this subfamily of spider crabs.     

A comparative study of the larval development of Monodaeus couchi (Couch), Xantho incisus Leach and Pilumnus hirtellus (Linnaeus) (Crustacea: Brachyura: Xanthidae)

Summary

Comparative accounts are given of the larval and first crab stages of three crab species belonging to the family Xanthidae: Monodaeus couchi (Couch), Xantho incisus Leach and Pilumnus hirtellus (Linnaeus). Features are discussed that distinguish the larvae of these species from those of other N.E. Atlantic brachyrhynch crabs.     

Attachment site selection of Hydrachna and Eylais (Acari: Hydrachnellae) watermite larvae infecting Corixidae (Hemiptera: Heteroptera)

The sites of attachment of four larval watermite species were recorded from four corixid species in Lough Corrib, Ireland. Parasitic watermites exhibited preferences in respect of attachment sites on the corixid hosts and these patterns were consistent for all host species examined. Hydrachna cruenta utilized areas of the host which were in direct contact with the water, the distribution of larvae reflecting the general behaviour and microdistribution of the hosts. Hydrachna conjecta infected the ventral hemielytra with a significant asymmetrical distribution on the right hemielytron, resulting from the folding pattern of the hemielytra and the larval route of entry to the subhemielytral air space. Eylais species attached to the abdominal terga of the host, E. infundibulifera infecting the anterior two terga and E. discreta terga three and four. Cymatia bonsdorffi was not parasitized by E. infundibulifera and on this host the majority of E. discreta attached to the second abdominal tergite. Eylais species infecting small corixid hosts may avoid interference competition with H. conjecta by attaching to the left side of the abdomen. Attachment site selection may contribute towards alleviation of intraspecific and interspecific interference competition for larval growing space.     

The zoeal development of Nanocassiope granulipes (Sakai, 1939) (Crustacea: Decapoda: Brachyura: Xanthidae) described from laboratory-reared material

Ovigerous crabs of Nanocassiope granulipes (Sakai, 1939) were collected in South Korean waters and their larvae reared in the laboratory. Four zoeal stages are described and illustrated in detail. Morphological characteristics of zoea I, such as the antennal exopod, the endopod of the second maxilliped and the telson, are compared with other known first-stage zoeas from the Xanthinae. The firststage zoea of N. granulipes appears to be similar to those of Leptodius exaratus (H. Milne Edwards, 1834) and Macromedaeus distinguendus (de Haan, 1835).     

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 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.     

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.     

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.     

The Cassidininae Hansen, 1905 (Crustacea: Isopoda: Sphaeromatidae) of Australia

The Cassidininae of Australia are revised. The status of the subfamily is assessed and it is concluded that, as presently constituted, the Cassidininae is an artificial taxon. It is maintained here as a taxon of convenience (sensu lato) until the other sphaeromatid subfamilies can be reassessed, but a new diagnosis (sensu stricto) is given. The genus Cassidina is redescribed. Three new genera are established: Agostodina gen. nov. (type species: A. munta sp. nov.), Apemosphaera gen. nov. (type species: A. naranagi sp. nov.) and Discidina gen. nov. (type species: D. banawarra sp. nov.). New diagnoses are provided for the genera Cassidina Milne Edwards, Chitonopsis Whitelegge, Cassidinidea Hansen, Paracassidina Baker, Syncassidina Baker and Platysphaera Holdich and Harrison. The genus Dies is placed in synonymy with Cassidinidea and an annotated list is given of all species of the genus. The following new species (excluding the new type species) are described: Chitonopsis booyoolie, Agostodina munta, Paracassidina anasilla, P. bakeri, P. bamarook, P. bilbie, P. cervina, P. dama, P. fuscina, P. incompta, P. kutyo, P. munna, P. petala, P. prolata, P. wurrook and Cassidinidea korpie. Keys to the Australian genera and species are given.     

The Harpacticoida (Crustacea: Copepoda) of two beaches in south-east India

Summary

Ten species of harpacticoid copepods were collected from two estuarine beaches near Porto Novo, south-east India. Three are described as new species. Two other species add to our knowledge of intra-specific variation in this group of animals.     

Decapod Crustacea from the International Indian Ocean Expedition: larval and postlarval stages of 3 species of Metapenaeopsis Bouvier (Penaeidae: Penaeinae)

Mysis and postlarval stages in the development of Metapenaeopsis mogiensis (Rathbun), M. andamanensis (Wood-Mason) and M. barbata (De Haan) are described and illustrated. Assignment to species of these developmental stages is tentative but supported by their distributions. Postlarvae of Metapenaeopsis resemble those of Penaeopsis but differ in possessing a dorsal abdominal carina. Metapenaeopsis closely resembles other members of the family but they are all differentiated by distinct characters. The diagnostic characters and the resemblances are discussed in this paper.     

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.