Ione Madinabeitia

CHALIMUS STAGES OF CALIGUS LATIGENITALIS (COPEPODA: CALIGIDAE) PARASITIC ON BLACKHEAD SEABREAM FROM JAPANESE WATERS, WITH DISCUSSION OF TERMINOLOGY USED FOR DEVELOPMENTAL STAGES OF CALIGIDS

Abstract The first and third chalimus stages and chalimus adult (previously known as young adult) of Caligus latigenitalis are described based on new material collected from the body surface of a heavily infected wild blackhead seabream Acanthopagrus schlegelii schlegelii from Hiroshima Bay, Japan. The second and fourth chalimus stages of the same species are redescribed. Adults of C. latigenitalis are characterized by possessing 2 stout marginally indented processes at the base of 2 terminal spines at distal exopodal segment of leg 4. The chalimi were identified to stage based on the structure of the frontal filament and the discrete ranges in body length. Sexual dimorphism is first observed at the third chalimus stage in the shape of the distal segment of the antenna. The total number of postnaupliar stages of C. latigenitalis is 6, including 4 semaphoronts, i.e., 1 copepodid stage consisting of 1 infective copepodid and the chalimus copepodid, 4 chalimus stages, and 1 adult stage with 1 chalimus adult and 1 mobile adult. New terminology for the developmental stages of caligid copepods is proposed herein by amending the definition of chalimus as the postnaupliar stages, as well as semaphoronts having a frontal filament for host attachment.

Assessing responses of the Hiroshima Bay ecosystem to increasing or decreasing phosphorus and nitrogen inputs.

The Japanese Government is seeking an appropriate level of nutrient load from the land to maintain the highest possible estuarine fishery production and water transparency simultaneously. To provide a scientific basis for the governmental inquiry, we conducted sensitivity analyses using an ecosystem model of Hiroshima Bay in order to assess the ecosystems responses to phosphorus and nitrogen inputs. Load levels of phosphorus (Case P), nitrogen (Case N) and both phosphorus and nitrogen (Case NP) that were different from the average loading recorded during 1991-2000 (±25%, ±50%, and ±75%) were applied. The results showed that phosphorus had a significantly greater impact on the primary production of the bay than nitrogen. Case P+25 increased the primary production but led to N-limitation. However, it was found that Case NP at the levels over +25% could bring the Hiroshima Bay ecosystem back to its eutrophic state of 30 years ago.

A New Species of Capillaria (Nematoda: Capillariidae) from the Intestine of the Marine Fish Acanthopagrus schlegelii schlegelii (Sparidae) from Japan

Abstract A new nematode species, Capillaria acanthopagri n. sp. (Capillariidae), is described from the intestine of the marine fish (black porgy) Acanthopagrus schlegelii schlegelii (Bleeker) from coastal waters of the western north Pacific Ocean off Kochi, Shikoku Island, Japan. The new species, belonging to the subgenus Neocapillaria Moravec, 1987, differs from other congeneric species of this subgenus from marine fishes (with the exception of C. navonae Timi, Rossin and Lanfranchi, 2006) mainly in the length (204–285 µm), shape, and structure of the spicule; and except for C. cooperi Johnston and Mawson, 1945, in markedly small body measurements (males and females 3–4 and 6–10 mm long, respectively). It is characterized by the presence of 33–43 elongate stichocytes; a heavily sclerotized spicule with rough transverse grooves; a spinous spicular sheath; and by eggs measuring 27–30 × 57–60 µm, without protruding polar plugs. Capillaria acanthopagri n. sp. is the first known species of Neocapillaria parasitizing fishes of the perciform Sparidae and the second species of this subgenus recorded from fishes of the Pacific Ocean.

Four new species of Colobomatus (Copepoda: Philichthyidae) parasitic in the lateral line system of marine finfishes captured off the Ryukyu Islands, Japan, with redescriptions of Colobomatus collettei Cressey, 1977 and Colobomatus pupa Izawa, 1974

This study describes four new species of Colobomatus Hesse, 1873 and redescribes Colobomatus collettei Cressey, 1977 and Colobomatus pupa Izawa, 1974 based on females collected from the sensory canals of seven finfish species from off the Ryukyu Islands, southern Japan. Colobomatus pteroisi sp. nov. from Pterois volitans is unique in having a mid-lateral pair of cephalic processes; Colobomatus acanthuri sp. nov. from Acanthurus olivaceus possesses a short neck between the head and first pair of thoracic processes and tiny spinules and three claws apically on the cephalic, thoracic and genital processes; Colobomatus gymnocranii sp. nov. from Gymnocranius griseus has an anterior pair of papillose thoracic processes that are twice as long as the posterior pair of spinulose processes; Colobomatus absens sp. nov. from Pterocaesio digramma is unique in lacking a posterior pair of thoracic processes. New host and locality records for C. collettei and C. pupa are also reported herein. http://www.zoobank.org/urn:lsid:zoobank.org:pub:BEB140D5-8936-4B47-B8B9-738BFABF37E1

Double-netting: an alternative approach for the recovery of parasitic copepods from finfishes

An alternative approach for the recovery of parasitic copepods from finfishes is proposed herein by applying double-netting (DN) after visual scanning (VS). Double-netting consists of double-filtering the dislodged debris after washing and shaking all dissected parts visually scanned previously. During DN, two different sized hand-nets (≤200 μm in mesh size) are used simultaneously. The debris entangled in the first net is recovered by washing the first net in the second one. A total of 1448 copepods were recovered from nine sparid finfish species by applying DN, accounting for 25% of the total. The most abundantly recovered copepods were bomolochids and philichthyids. Our double-sieving method is efficient in recovering overlooked copepods by VS, providing more accurate results in diversity and quantitative studies. Additional advantages of DN include its simplicity (small size and weight), low price (less than US

A new species of Procolobomatus Castro Romero, 1994 (Copepoda: Philichthyidae) endoparasitic in a deepwater longtail red snapper (Actinopterygii: Lutjanidae) off Ishigaki Island, Japan, with records of philichthyid copepods reported from Asian waters

3), and convenience (easy to transport and apply directly in the field).

Description of Naobranchia Denticis N. Sp. (Copepoda, Siphonostomatoida, Lernaeopodidae) Parasitic on Dentex Hypselosomus (Teleostei, Sparidae) from Japanese Waters, with a Key to the Species of Naobranchia

A new species of the Philichthyidae Vogt, 1877 (Copepoda: Poecilostomatoida), Procolobomatus hoi n. sp., is described based on adult female specimens recovered from the cephalic sensory canals of Etelis coruscans Valenciennes (Actinopterygii: Lutjanidae) caught off Ishigaki Island, the Ryukyu Islands, southern Japan. The new species differs from its congeners by having the following combination of characters: a long medial cephalic lobe about one-third the length of the body; an armature of five spines on the distal exopodal segment of leg 2; one long apical seta on the papillose leg 4; a caudal ramus armed with one medial and four terminal setae (two middle setae are inflated); and spinulose ornamentation covering the body. Procolobomatus hoi n. sp. is the first member of the genus reported from the western Pacific Ocean and from a host of the family Lutjanidae. Previous records of philichthyid copepods from Asian waters are also reported.

Planktonic Phases in Symbiotic Copepods: a Review

[The adult female of Naobranchia denticis n. sp. is described based on material collected from the gill filaments of the yellowback seabream Dentex hypselosomus caught in the southern Sea of Japan off the northern coast of Kyushu. Characteristic features of the new species include a cephalothorax three times as long as the trunk, a trunk as wide as long, egg-sacs situated posterolateral to the trunk, without extending to the bases of the maxillae anteriorly, slightly inclined toward each other posteriorly, with three pairs of reinforcement ribbons; caudal rami longer than abdomen and digitiform; head with lateral adhesive lobes and 12 hyaline papillae. The male has not been found. Our finding represents the first report of Naobranchia species from Japanese sparid hosts and the fourth report of this genus from the coastal waters of Japan. A key to the 21 species of Naobranchia is also included herein. Three species ( N. bellones , N. pomolobi , and an unspecified species of Naobranchia from Hawaii) are not considered members of this genus because they lack the ribbonlike maxillae. La hembra adulta de Naobranchia denticis n. sp. es descrita basado en el material obtenido de los filamentos branquiales de la dorada de espalda amarilla Dentex hypselosomus capturado en el sur del Mar de Japon frente a la costa norte de Kyushu. Los rasgos caracteristicos de la nueva especie incluyen el cefalotorax tres veces mas largo que el tronco, un tronco tan ancho como largo, los ovisacos situados posterolateralmente al tronco, sin extenderse a las bases de los maxilares anteriormente, ligeramente inclinados el uno al otro en la region posterior, con tres pares de cintas de refuerzo; ramas caudales mas largas que el abdomen y digitiformes; cabeza con lobulos adhesivos laterales y 12 papilas hialinas. El macho no ha sido encontrado. Nuestro hallazgo representa el primer informe de especies de Naobranchia en hospedadores esparidos japoneses y el cuarto informe de este genero en las aguas costeras de Japon. Una clave de las 21 especies de Naobranchia tambien se ha incluido en este documento. Tres especies ( N . bellones , N. pomolobi , y una especie no especificada de Naobranchia de Hawai) no se consideran miembros de este genero porque carecen de los maxilares con forma de cinta. , The adult female of Naobranchia denticis n. sp. is described based on material collected from the gill filaments of the yellowback seabream Dentex hypselosomus caught in the southern Sea of Japan off the northern coast of Kyushu. Characteristic features of the new species include a cephalothorax three times as long as the trunk, a trunk as wide as long, egg-sacs situated posterolateral to the trunk, without extending to the bases of the maxillae anteriorly, slightly inclined toward each other posteriorly, with three pairs of reinforcement ribbons; caudal rami longer than abdomen and digitiform; head with lateral adhesive lobes and 12 hyaline papillae. The male has not been found. Our finding represents the first report of Naobranchia species from Japanese sparid hosts and the fourth report of this genus from the coastal waters of Japan. A key to the 21 species of Naobranchia is also included herein. Three species ( N. bellones , N. pomolobi , and an unspecified species of Naobranchia from Hawaii) are not considered members of this genus because they lack the ribbonlike maxillae. La hembra adulta de Naobranchia denticis n. sp. es descrita basado en el material obtenido de los filamentos branquiales de la dorada de espalda amarilla Dentex hypselosomus capturado en el sur del Mar de Japon frente a la costa norte de Kyushu. Los rasgos caracteristicos de la nueva especie incluyen el cefalotorax tres veces mas largo que el tronco, un tronco tan ancho como largo, los ovisacos situados posterolateralmente al tronco, sin extenderse a las bases de los maxilares anteriormente, ligeramente inclinados el uno al otro en la region posterior, con tres pares de cintas de refuerzo; ramas caudales mas largas que el abdomen y digitiformes; cabeza con lobulos adhesivos laterales y 12 papilas hialinas. El macho no ha sido encontrado. Nuestro hallazgo representa el primer informe de especies de Naobranchia en hospedadores esparidos japoneses y el cuarto informe de este genero en las aguas costeras de Japon. Una clave de las 21 especies de Naobranchia tambien se ha incluido en este documento. Tres especies ( N . bellones , N. pomolobi , y una especie no especificada de Naobranchia de Hawai) no se consideran miembros de este genero porque carecen de los maxilares con forma de cinta. ]

Contribution of Ju-shey Ho to the systematics of symbiotic copepods of Japan

Abstract In symbiotic copepods, most naupliar stages are typically planktonic, playing a primary role in dispersal, while the first copepodid usually represents the infective stage. Later copepodid stages, including adults, are associated with host organisms. Many symbiotic copepods have abbreviated life cycles, with a reduced number of naupliar stages and two different feeding habits. These patterns are presumably related to distinct life cycles strategies. Exceptional cases are exemplified by members of the Monstrillidae and Thaumatopsyllidae, both of which are protelean parasites, with infective nauplii and non-feeding planktonic adults. In the Caligidae, the life cycle follows a generalized pattern, but adults of many species like Caligus undulatus seem to exhibit a dual mode of life involving host switching. Adults leaving the first host become temporarily planktonic before attaching to the final host. This dual mode of life is also found in adults of the Ergasilidae. Abbreviation of the planktonic phase is characteristic for some symbiotic taxa, thus suggesting that they have evolved to become highly efficient in locating and infecting new hosts without needing long-distance larval dispersal. The life cycle of copepods associated with zooplankters is also briefly reviewed. Zooplankters are clearly less used as hosts by copepods than benthic invertebrates. It is likely that symbiotic copepods dynamically utilize planktonic phases in their life cycle, thus maintaining the balance between dispersal, host location, reproduction, and predator-avoidance strategies.

Redescription of Pseudacanthocanthopsis secunda (Yamaguti and Yamasu, 1960) (Copepoda: Chondracanthidae) parasitic on marine fishes from the Seto Inland Sea, Japan and the East China Sea off Japan and Korea

This note reviews the work done by Ju-shey Ho, currently Professor Emeritus at California State University, Long Beach, CA, USA, on the systematics of symbiotic copepods from aquatic animals in Japanese waters. Since 1980, he has reported 110 species of symbiotic copepods from Japanese fish and marine invertebrates, including those representing one new family, seven new genera and 41 new species, and has greatly contributed to clarifying the symbiotic copepod fauna of Japan. Research using symbiotic copepods as bioindicators of the phylogeny and evolution of host animals was conducted by him for the first time in Japan. He also made significant contributions to the taxonomy and biology of caligid copepods, a group that poses a serious threat to the aquaculture industry, found on farmed fish in Japan.