The lunule of caligid copepods: an evolutionarily novel structure.

Nearly half of the genera of the family Caligidae possess an evolutionarily novel structure called the "lunule" on the ventral surface of the frontal plate. Lunules are paired cup-like suckers that assist in securing attachment of the copepod parasite to its host. Although present in genera such as Caligus and Pseudocaligus, lunules are absent in other caligid genera such as Lepeophtheirus as well as in more primitive caligiforms such as members of the families Trebiidae and Dissonidae. We compared the morphology and development of the anterior margin of the frontal plates between two caligids, Pseudocaligus fugu and Lepeophtheirus sekii, and a more basal caligiform, Dissonus heronensis (a dissonid), using scanning electron, transmission electron, and laser confocal microscopes. Our observations suggest that the lunules originated as a modification of the marginal membranes of the ancestral frontal plates. We also demonstrated the presence of an anlagen cell population for the lunule and marginal membrane in the developing frontal plate. These primordial cells can be detected as early as the first stage of the chalimus phase. Based on these observations, an evolutionary scenario for the lunule is proposed based on cytological evidence. This case study enhances our understanding of "evolutionary novelty," which is a main focus of contemporary evolutionary developmental biology.

First record of the Gloiopotes huttoni (Thomson, 1890) (Copepoda: Caligidae) parasitic on the swordfish Xiphias gladius along the southeast coast of India.

Parasitic copepods infect a large number of fishes. In particular, the family Caligidae (Crustacea) comprises more than 450 species worldwide, some of which are harmful to cultured and wild fishes. Recently, we found a parasitic copepod on the host swordfish Xiphias gladius (Xiphidae) in the coastal waters of Parangipettai, southeast coast of India. It was identified as Gloiopotes huttoni by its morphological features, and it belongs to the family Caligidae (order Siphonostomatoida). The swordfish was highly infected with about 72 caligids on a single host. Both male and female forms of G. huttoni were colonized on the beak of the swordfish and distributed mostly along the upper and lower jaws of the host, with 42 and 30 copepod parasites, respectively. Most of the copepods were ovigerous, and more females than males were recorded. It is the first record of the occurrence of G. huttoni in India.

A new species of bomolochid Orbitacolax brevispinus n. sp. and redescription of taeniacanthid Cirracanthus inimici (Yamaguti et Yamasu, 1959) (Crustacea: Copepoda: Cyclopoida) parasitic on marine fishes of Korea.

Two species of cyclopoid copepods are recorded in this study. (1) A new species of bomolochid, Orbitacolax brevispinus n. sp. (Crustacea) is described based on adult females collected from the gill filaments and inner surface of the opercula of red barracuda, Sphyraena pinguis Günther (Perciformes: Sphyraenidae), captured in Korean waters. The new species differs from its congeners by the possession of two pairs of spines on the dorsal surface of the cephalothorax located just posterior to the rostrum and a different setal formula on the distal exopodal segments of legs 2-4. (2) A taeniacanthid Cirracanthus inimici (Yamaguti et Yamasu, 1959) (Crustacea) is redescribed based on the specimens collected from the gill filaments and inner surface of the opercula of devil stinger, Inimicus japonicus (Cuvier) (Scorpaeniformes: Synancellidae). This finding is the first record in Korean waters and the first description of male. A checklist of parasitic copepods of the families Bomolochidae Sumpf, 1871 and Taeniacanthidae Wilson, 1911of Korea is also provided.

Accumulation of tetrodotoxin (TTX) in Pseudocaligus fugu, a parasitic copepod from panther puffer Takifugu pardalis, but without vertical transmission--using an immunoenzymatic technique.

The caligid copepod Pseudocaligus fugu, a common parasite on the body surface of both toxic (Takifugu pardalis) and cultured, non-toxic (Takifugu rubripes) puffer fishes, was isolated and analyzed for the presence of tetrodotoxin (TTX) using a monoclonal anti-TTX antibody-based immunohistochemical technique. Histological sections of female P. fugu from Takifugu pardalis explicitly revealed that positive brown staining was visible in regions of gut and appendages, and also in the general body tissues from the prosome to the urosome. It is absent from the epicuticle, ovary, oviduct, uterus and egg sacs, where clear negative blue color reaction was obtained. In contrast, the caligids on cultured, non-toxic Takifugu rubripes, considered as negative control, had no sign of TTX. The results indicate that there is no vertical transmission of TTX in the parasitic caligids, which could acquire TTX by feeding on the toxic mucus and skin tissues of host puffer fish.

Two new species of benthopelagic Stephos (Copepoda, Calanoida, Stephidae) from Korea.

Two new species of benthopelagic copepods of the genus Stephos T. Scott, 1892, belonging to the family Stephidae G.O. Sars, 1902, are described based on specimens collected in the stagnant water flooding the burrows excavated by ocypodid crabs in two intertidal mud-flats, and from near-bottom shallow waters in Korea, respectively. They can be easily diagnosed based on the ornamentation of both the female genital double-somite and genital operculum; the morphology of the distal segment of the male right P5; the presence/absence of a tiny pointed process on the distomedial angle of second segment of female P5; and the condition (seta or spine) of the lateral armature element on the distal segment of female fifth legs, among other features. This is one of the few cases reported of calanoid copepods living as commensals of other invertebrates, and raises to six the number of members of the genus reported from Asia. This is also the first record of the family Stephidae in Korea.

First records of parasitic copepods (Crustacea, Siphonostomatoida) from marine fishes in Korea.

The knowledge of the biodiversity of parasitic copepods in South Korea is increasing. Interestingly we report here, some parasitic copepods considered as the first record of findings from Korea. Nine species of parasitic copepods (Siphonostomatoida) including six genera of three different families [Caligidae (7), Lernaeopodidae (1), Lernanthropidae (1)] were recovered from eight species of wild fishes in Korea: 1) Caligus hoplognathi Yamaguti & Yamasu, 1959 (♀, ♂) from the body surface of barred knifejaw Oplegnathus fasciatus (Temminck & Schlegel); 2) Caligus lagocephali Pillai, 1961 (♀) from the gills of panther puffer Takifugu pardalis (Temminck & Schlegel); 3) Euryphorus brachypterus (Gerstaecker, 1853) (♀, ♂) from the opercular cavity of Atlantic bluefin tuna Thunnus thynnus (Linnaeus); 4) Euryphorus nordmanni Milne Edwards, 1840 (♀, ♂) from the opercular cavity of common dolphin fish Coryphaena hippurus Linnaeus; 5) Gloiopotes huttoni (Thomson) (♀, ♂) from the body surface of black marlin Istiompax indica (Cuvier); 6) Lepeophtheirus hapalogenyos Yamaguti & Yamasu, 1959 (♀) from the gill filaments of O. fasciatus; 7) Lepeophtheirus sekii Yamaguti, 1936 (♀, ♂) from the body surface of red seabream Pagrus major (Temminck & Schlegel); 8) Brachiella thynni Cuvier, 1830 (♀) from the body surface of longfin tuna or albacore Thunnus alalunga (Bonnaterre); 9) Lernanthropinus sphyraenae (Yamaguti & Yamasu, 1959) (♀) from the gill filaments of moon fish Mene maculata (Bloch & Schneider). Since the female was already reported in Korea, it is a new record for the male of C. hoplognathi. A checklist for the parasitic copepods of the family Caligidae, Lernaeopodidae and Lernanthropidae of Korea is provided.

Occurrence of parasitic copepods in Carangid fishes from Parangipettai, Southeast coast of India.

In the present study, 68 fishes were infested out of 544 specimens examined from six different species of Carangid fishes which were collected from Parangipettai coastal waters. Eight species of parasitic copepods were found on gill filaments, body surface and nasal capsule regions. The maximum prevalence was recorded in Carangoides malabaricus (22.5 %) and minimum was noticed in (2.4 %) Selaroides leptolepis. The intensity of infection ranged from 1 to 1.2. Thus, considerable variation in the respiratory area was observed owing to the attachment of parasites in the infected fishes. Caligus sp. and C. epidemicus parasites were attached to body surface and only one Sphyriid sp. parasites were found in nasal capsule region. It is very difficult to estimate the actual harm to fish caused by the presence of parasites; if this is uneasy in cultured fish, it is almost impossible in feral fish populations. It should also be emphasized that the presence of a parasite does not necessarily imply manifestation of a disease. In aquaculture, some parasites are able to reproduce rapidly and heavily infect a large proportion of fish which may lead to diseases with significant economic consequences.

Three new records of copepods (Siphonostomatoida) parasitic on marine fishes of Iraq, including the relegation of two species of Lernanthropinus to Lernanthropinus temminckii (von Nordmann, 1864).

Three parasitic copepods (Siphonostomatoida) belonging to three different genera were recovered from marine fishes of Iraq, and are listed here as new records. The sea lice Caligus epinepheli Yamaguti, 1936 (Caligidae) was collected from the Japanese threadfin bream, Nemipterus japonicus (Bloch). It had been frequently reported from teleost fishes around the world. The second record, comprising male and female, was another caligid, rarely caught from fishes - Hermilius longicornis Bassett-Smith, 1898, collected from the giant catfish, Netuma thalassina (Rüppell). This paper features the first description of the male of the latter species. The third record was the lernanthropid, Lernanthropinus temminckii (von Nordmann, 1864) (Lernanthropidae), redescribed based on the specimens collected from the greater lizard fish, Saurida tumbil (Bloch) (Synodontidae). In order to clarify its taxonomic status, our specimen was compared with the holotype of L. gibbosus (Pillai, 1964) from the collections of Zoological Survey of India, Kolkata, and the syntypes of L. sauridae Do in Ho and Do, 1985 and L. temminckii from the collections of the Smithsonian Institution, Washington D.C. We found similarities in the morphology of the body, mouthparts, and legs 1-4 in three above-mentioned species. The prominent feature, the setation pattern of legs 1 and 2 was similar in all the female specimens examined. In the light of this, we formally relegate L. gibbosus and L. sauridae to synonymy with L. temminckii. Another important similarity is that Lernanthropinus gibbosus, L. sauridae, and L. temminckii have exclusively been parasitic on lizardfishes (Synodontidae). The attachment site of all three copepods reported form Iraq were the gill filaments.

Infestation of Lernaeenicus seeri (Copepoda: Pennellidae) and Hirudinella ventricosa (Digenea: Hirudinellidae) on wahoo Acanthocybium solandri collected from Parangipettai, southeast coast of India.

A commercially important fish, wahoo Acanthocybium solandri (Cuvier, 1832) (Scombridae), was collected to study the infestation of parasites from Parangipettai landing center, Tamil Nadu, southeast coast of India for a period of one year from January to December 2011. A total of 644 fish were captured and screened for parasites. Off 644 fish, 270 were infested by a parasitic copepod Lernaeenicus seeri Kirtisinghe, 1934 (Siphonostomatoida: Pennellidae) on the body surface. It is a mesoparasite, since the head and neck are inserted and attached to the muscle by making a wound/hole on the body and the rest of the parasite body with the egg sacs hanging outside. Prevalence was recorded as 42.29% with mean and maximum intensity at 3.22 and 33, respectively. Seasonal study showed that the prevalence was highest (62.82 %) during postmonsoon. Simultaneously, some of the fish (n = 144) were internally observed for the presence of parasites and we found that 101 fish were infested with an endoparasite digenean Hirudinella ventricosa (Pallas, 1774) (Hirudinellidae) in the stomach. Prevalence was recorded as 70.9%, and mean intensity of 1.62 and maximum intensity of 3 were also noted. The overall percentage of both copepod and digenean infestation were recorded as 60.42%. The infestation was high in postmonsoon season for both parasites. This is the first record of L. seeri from Indian waters and the second record of occurrence worldwide. Significant interactions were observed between season and infestation of both parasites (P<0.05).

Seasonal occurrence and habitat of two pennellids (Copepoda, Siphonostomatoida) infecting marine ranched black scraper and Korean rockfish in Korea.

The seasonal occurrence and habitat of two parasitic copepods, Peniculus minuticaudae (Shiino, 1956) and Peniculus truncatus (Shiino, 1956) (Siphonostomatoida, Pennellidae) infecting the fins of black scraper Thamnaconus modestus and Korean rockfish Sebastes schlegelii, respectively were investigated. The fishes were collected from Tongyeong marine living resources research and conservation center, southern coast of Korea as five per month for two years from July 2011 to June 2013. In total, 391 copepods of P. minuticaudae were collected in two years, in contrast to P. truncatus. Prevalence was 85%, mean intensity was 3.25, and maximum intensity was 33. Season wise, the infestation was observed as the highest in autumn (September-November) season, and the lowest in winter (December- February). It was infested only on fins of black scrapers. Abundance of P. minuticaudae was found on the pectoral fin (43.5%), followed by anal (22.5%), second dorsal (20.5%) and caudal fins (13.5%). Statistically significant interactions were observed between season, infestation and infected regions (P<0.001). It is also reported for the first time in Korea from the fins of wild threadsail filefish Stephanolepis cirrhifer from Busan, Jeju, Tongyeong and Yeosu fish markets. It can be a new record on its host and localities. A total of 51 P. truncatus were collected with the prevalence of 37.5%, mean intensity of 0.37 and maximum intensity of 6. Season wise, infestation was observed as the highest in summer (June-August), and the lowest in winter. Attachment site was the dorsal fin and not found from any other fins of rockfish. Statistically significant interaction was observed between season and infestation (P<0.05). This is the first report on the ecology of these two pennellids.