Chonopeltis australis (Crustacea: Branchiura); the female reproductive system.

The female reproductive system has been described for Dolops ranarum (Stuhlman, 1891) and various Argulus spp. but, there is no description of the reproductive system for Dipteropeltis spp. Calman, 1912 or Chonopeltis spp. Thiele, 1900. This paper describes the female reproductive system and egg laying behaviour of Chonopeltisaustralis Boxshall, 1976 using histology, light microscopy, scanning electron microscopy and observations. The histological study of six specimens showed that the organ structure is similar to that of Argulus spp. and D. ranarum. The oocytes therefore develop in the gonocoel, are ovulated into the lumen of the ovary which is continuous with the functional oviduct and eventually the gonopore. Females of C. australis deposit eggs on the surrounding substrate while the fish is at rest, without leaving the host, thereby mitigating the risk of not locating a host again.

Rediscovery of Chonopeltis meridionalis Fryer, 1964 (Crustacea: Branchiura) from Labeo rosae Steindachner in the River Olifants, Mpumalanga, and the taxonomic status of C. victori Avenant-Oldewage, 1991 and C. koki Van As, 1992.

Chonopeltis Thiele, 1900 presently comprises 14 species, it is endemic to Africa and its species show a high degree of host-specificity towards fish families and in some cases, individual fish species. Chonopeltis meridionalis Fryer, 1964 was originally described from Labeo rosae Steindachner collected in the River Nuanetsi in Rhodesia, now Zimbabwe, Limpopo River System. At the time of description C. meridionalis was the most southerly species of the genus. Chonopeltis victori Avenant-Oldewage, 1991 was described from the River Olifants, Mpumalanga, South Africa, which also forms part of the Limpopo River System. The host fish was Labeo rosae and Labeobarbus marequensis (A. Smith), whilst C. koki Van As, 1992 was described from Labeo cylindricus Peters, collected in the River Zambezi, Eastern Caprivi, Namibia. During surveys conducted in 2012, additional material of a species of Chonopeltis was collected from Labeo rosae in the River Olifants. Upon closer examination, the new material was identified as C. meridionalis. Further investigation revealed that C. victori and C. koki share a number of characteristics with C. meridionalis. This paper provides the first scanning electron microscopy of C. meridionalis, includes additional information on fully-mature as well as sub-adult males and females. Finally, it was concluded that C. victori and C. koki are junior synonyms of C. meridionalis.

Histological and ultrastructural investigation of the female reproductive system of Argulus bengalensis Ramakrishna, 1951 (Crustacea: Branchiura).

In order to understand branchiuran reproductive biology, it is imperative to know the sites of oogenesis and oocyte maturation, locate the accessory reproductive glands, and identify the fertilization site with the present knowledge of the sperm transfer mechanism of the genus Argulus. With these objectives, we attempted to describe the female reproductive system of Argulus bengalensis using serial histological sections through the ovaries and associated ducts in the transverse, longitudinal, and sagittal planes. The reproductive organs include a median ovary, one pair of ovarian lumina, a median oviduct, and a pair of collateral accessory glands. A duct from each of the collateral accessory glands leads into the proximal part of the median oviduct, which opens to the exterior through a genital opening at the distal end. The glandular secretion presumably contributes to the jelly coat of the egg. The ovary is bound with a tunica propria which extends further diametrically inside the ovary forming the paired lumina. The lumina are confluent into the median oviduct. Two distinct areas, the germarium and differentiating zones, are clearly distinguishable within the ovary. The tunica propria itself houses the oogonia within a matrix, serving as the germarium. Transmission electron micrograph reveals that the matrix is made of collagen. The collagen matrix confers elasticity to the tunica propria to accommodate the postvitellogenic oocytes within the ovarian lumen. The differentiating zone is situated in between the germarium: dorsally it is covered with a chromatophore layer. The ovary is ensheathed by a circum ovarian striated muscle. The presence of spermatophores in the ovarian lumen indicates the fertilization site. J. Morphol. 277:707-716, 2016. © 2016 Wiley Periodicals, Inc.

A scanning electron microscopy study of Argulus vittatus (Rafinesque-Schmaltz, 1814) (Crustacea: Branchiura) from Algerian coast.

A study of the Algerian Branchiura, Argulus vittatus (Rafinesque-Schmaltz, 1814) was conducted using the scanning electron microscopy (SEM). New morphological features are reported for the first time (mouth con, first maxilla, second maxilla, structures and ornamentation of thoracic segments, structure of semen papillae, etc.). The morphology of small and large female specimens was compared. Two new hosts, Pagellus erythrinus L. and Sparus aurata L., are reported for this species. Until now, six host species were reported for A. vittatus, and stenoxenic specificity for Sparid fishes was observed for Algerian specimens. The biogeographical distribution of this species seems to be restricted to the eastern coast of Algeria. Additional information about the host specificity, ecology, and life cycle of this parasitic species were given.

Expanded description of Dolops bidentata (Bouvier, 1899) (Branchiura: Argulidae) based on specimens collected on Pygocentrus nattereri Kner, 1858 (Characiformes) from Poconé Wetland, MT, Brazil.

The current information on the branchiuran Dolops bidentata, a species described more one hundred years ago, is valid but incomplete; hence, an expanded description is given herein. Additional morphological information was obtained by light and scanning electron microscopy from specimens collected on Pygocentrus nattereri from the Poconé Wetland, MT, Brazil. Description of the appendages and other structures such as respiratory area, mouth, details and ornamentation of antennules and maxillae are provided for the first time.

Argulus japonicus: sperm transfer by means of a spermatophore on Carassius auratus (L).

The process of sperm transfer is somewhat enigmatic in Argulus, even though copulation has been witnessed. A breeding colony of Argulus japonicus was kept under laboratory conditions in order to study reproduction in the species. Pairs in copula were removed and studied with histology and scanning electron microscopy to describe the mechanism of sperm transfer. Sections of copulating pairs revealed sperm on the accessory copulatory structures of the male's swimming legs; and scanning electron microscopy showed that sperm transfer occurs in three phases which can be differentiated to 10 different stages. Sperm transfer occurs via a spermatophore which is extruded from the genital aperture of the male and is then transferred to the socket on the third pair of legs of the male, before being transferred into the spermathecae of the female via the spermathecal spines. This is the first observation of a spermatophore in Argulus.

The little-known Dipteropeltis hirundo Calman, 1912 (Crustacea, Branchiura): SEM investigations of paratype material in light of recent phylogenetic analyses.

The Branchiura are fish ectoparasites which include the well-known and very commonly found genus Argulus. But the Branchiura also contains the monotypic genus Dipteropeltis, about which only very little is known. In this investigation of two female paratype specimens we describe for the first time the external morphology of Dipteropeltis based on Scanning Electron Microscopy. We show that Dipteropeltis has a pre-oral spine, unique suction disc support structures, an Argulus-like mouth cone and second maxillae with a combination of features seen in both Argulus and Chonopeltis. These data are compared with data from the three remaining branchiuran genera Dolops, Chonopeltis and Argulus and discussed in a phylogenetic context based on a recently proposed phylogeny of the group.

Ultrastructure of Argulus japonicus Thiele, 1900 (Crustacea: Branchiura) collected from Guangdong, China.

Argulus japonicus Thiele, 1900 was originally described from China, but has spread to Europe, Africa, Australia, and North America. An ultrastructural description of A. japanicus has been done as one of the most common fish ectoparasites which has a high affect on fish life. The description was based on light and scanning electron microscopes studies using 13 females and 7 males which were collected from Shunde city in Guangdong Province, China. Typical Argulus body and body's appendages are associated with our specimens, carapace covers fourth leg, and scales separate uniformly on frontal and lateral lobes, ventral surface of thorax is ornamented by scales contrary of the dorsal surface which is quite smooth, various shapes of scales have been detected on second maxillae. Location and structure of copulatory accessory, number and structure of overlapping sclerites of sucking disk rim, melanophores patches of male, second swimming leg structure, and parasite's total size are the most important criteria which may be used to distinguish between male and female. Moreover, new classification criteria of Argulide, obtained by scanning electron microscopic study of previous species, are discussed.

Redescription of Argulus multipocula Barnard, 1955 (Crustacea: Branchiura) collected on the west coast of South Africa.

Argulus multipocula Barnard, 1955 was originally described from a single female found in a littoral sample from the east coast of South Africa. We present a redescription of this species based on light and scanning electron microscope studies of 25 females collected from the southern mullet Liza richardsonii (Smith) on the west coast of South Africa.