Developmental stages of fish blood flukes, Cardicola forsteri and Cardicola opisthorchis (Trematoda: Aporocotylidae), in their polychaete intermediate hosts collected at Pacific bluefin tuna culture sites in Japan.
Farming of Pacific bluefin tuna (PBT), Thunnus orientalis, is a rapidly growing industry in Japan. Aporocotylid blood flukes of the genus Cardicola comprising C. orientalis, C. opisthorchis and C. forsteri are parasites of economic importance for PBT farming. Recently, terebellid polychaetes have been identified as the intermediate hosts for all these parasites. We collected infected polychaetes, Terebella sp., the intermediate host of C. opisthorchis, from ropes and floats attached to tuna cages in Tsushima, Nagasaki Prefecture, Japan. Also, Neoamphitrite vigintipes (formerly as Amphitrite sp. sensu Shirakashi et al., 2016), the intermediate host of C. forsteri, were collected from culture cages in Kushimoto, Wakayama Prefecture, Japan. The terebellid intermediate hosts harbored the sporocysts and cercariae in their body cavity. Developmental stages of these blood flukes were molecularly identified using species specific PCR primers. In this paper, we describe the cercaria and sporocyst stages of C. opisthorchis and C. forsteri and compare their morphological characteristics among three Cardicola blood flukes infecting PBT. We also discuss phylogenetic relations of the six genera of the terebellid intermediate hosts (Artacama, Lanassa, Longicarpus, Terebella, Nicolea and Neoamphitrite) of blood flukes infecting marine fishes, based on their morphological characters.
Meguro Parasitological Museum, Tokyo 153-0064, Japan. Electronic address: ogawak@kiseichu.org.
Kazuo
K
Ogawa
Aquaculture Research Institute, Kindai University, Wakayama 649-2211, Japan.
Sho
S
Shirakashi
Aquaculture Research Institute, Kindai University, Wakayama 649-2211, Japan.
Kazuki
K
Tani
Aquaculture Research Institute, Kindai University, Wakayama 649-2211, Japan.
Sang Phil
SP
Shin
Aquaculture Research Institute, Kindai University, Wakayama 649-2211, Japan.
Katsuya
K
Ishimaru
Aquaculture Research Institute, Kindai University, Wakayama 649-2211, Japan.
Tomoki
T
Honryo
Nagasaki Prefectural Institute of Fisheries, Nagasaki 851-2213, Japan.
Yukitaka
Y
Sugihara
Kushimoto Marine Park, Wakayama 649-3514, Japan.
Hiro'omi
H
Uchida
D000818:Animals; D058487:Cercaria / Q000302:isolation & purification / Q000648:ultrastructure; D017931:DNA Primers; D021903:DNA, Ribosomal Spacer; D005393:Fish Diseases / Q000469:parasitology; D005398:Fisheries; D006790:Host-Parasite Interactions; D007564:Japan; D008018:Life Cycle Stages; D008853:Microscopy; D033661:Oocysts / Q000254:growth & development / Q000648:ultrastructure; D010802:Phylogeny; D011077:Polychaeta / Q000469:parasitology*; D016133:Polymerase Chain Reaction; D014200:Trematoda / Q000033:anatomy & histology* / Q000235:genetics* / Q000254:growth & development / Q000302:isolation & purification; D014201:Trematode Infections / Q000469:parasitology / Q000662:veterinary; D014413:Tuna / Q000469:parasitology
D017931:DNA Primers; D021903:DNA, Ribosomal Spacer
Aporocotylidae; Cercaria; Intermediate host; Sporocyst; Thunnus orientalis