Psenopsis Anomala Research Articles

Seasonal distribution and population genetic structure of Psenopsis anomala (Japanese butterfish) inferred from otolith oxygen isotope ratios and mitochondrial DNA

Psenopsis anomala (Japanese butterfish) is a commercially important fish species with a wide distribution in the Northwest Pacific Ocean, but its catch in Taiwanese waters has been declining for decades. This study aims to elucidate the migration pattern and population structure of P. anomala by analyzing otolith δ18O values, mitochondrial COI and cyt b sequences, respectively. The results reveal a seasonal migration pattern between the northern South China Sea and the Yellow Sea. Analysis of the haplotype network reveals that most P. anomala collected from each location share the haplotypes Hap1 and Hap5, while each population also has its own unique haplotypes. Analysis of molecular variance reveals that the primary variation (92.98%) is observed among individuals within the populations. Fu's FS test conducted for all populations showed no significant differences, and the mismatch distribution aligns with recent population expansion. Both the maximum likelihood tree and the median-joining network show no geographic population structuring in P. anomala samples from Japan and Taiwan. The combined findings from otolith microchemistry and genetic analysis suggests that P. anomala distributed in east Asia shall be managed as a single stock.

Impacts of climate events on life history parameters of major commercial fishes in the Beibu Gulf, South China Sea in the last 15 years

A detailed understanding of the impact of climate variability on fish life histories provides a fundamental basis for the ecosystem approach to fisheries management. In this study, we evaluated the relationship between fish life-history trait parameters and climate periods, using survey data from 2006−2020 for the Beibu Gulf of the northwestern South China Sea, a fishing ground with high commercial and ecological value. We show that climate events can significantly alter the structure of the life history for major commercial fishes, with more diverse life-history strategies during warm events and more concentrated mortality during cold events. Additionally, we detected special relationships between climate events and the life-history trait composite index (LTCI) inPsenopsis anomalaandTrichiurus lepturus. It is possible that other indicators would be more appropriate than variability in Oceanic Niño Index (ONI), such as variation in fishing effort or the environmental resistance of fish. Anthropogenic disturbance and biological features may also help explain the magnitude of population variability. We found that changes in life-history traits of only a few commercial fishes (Decapterus maruadsi,Pennahia macrocephalus, andUpeneus sulphureus) were related to the shift in climate periods; these fishes were generally characterized by faster growth and higher mortality rates in the normal and El Niño periods, with the opposite trends in La Niña periods. However, the emergence of climate events has led to a clear complementarity of life-history strategies among some fish in the same ecological niche (same genus and/or feeding group), which may be explained by a balance between habitat conditions and fishing pressures. This study of fish life-history strategies under climate anomalies provides key insights into important attributes for managers to consider when implementing relevant measures to promote fisheries sustainability in the subtropical bay.

Genetic structure and historical demography of the Pacific rudderfish Psenopsis anomala in the Northwestern Pacific Ocean

Genetic structure and historical demography of the Pacific rudderfish Psenopsis anomala in the Northwestern Pacific Ocean

Age and growth of the Japanese butterfish Psenopsis anomala in the waters off north-eastern Taiwan–Erratum

Age and growth of the Japanese butterfish Psenopsis anomala in the waters off north-eastern Taiwan–Erratum

Age and growth of the Japanese butterfish Psenopsis anomala in the waters off north-eastern Taiwan

AbstractThe catch of Japanese butterfish, Psenopsis anomala in Taiwan is greater than those of any other nation; however, the biology, particularly the age and growth, of this economically important fish species is little known. This study describes the age and growth of P. anomala based on 734 specimens (340 females, 363 males, 31 unsexed) caught by trawl fishery in the north-eastern waters off Taiwan from March 2007 to July 2008. The age of specimens was estimated by counting the growth annuli in sagittal otoliths. The periodicity of annulus deposition on otolith was estimated to be one year with opaque zone deposited between July and August based on marginal increment analysis. The maximum age for both sexes was estimated to be ~4. The female portion of the population was dominated by the 3+ age class, while the male portion was dominated by the 2∞ age class. The parameters of the von Bertalanffy growth function with standard error estimated based on the observed length at age using a non-linear method are as follows: L∞ = 25.47 ± 0.65 cm, k = 0.30 ± 0.03 year−1, and t0 = −1.84 ± 0.16 year for females (n = 350), and L∞ = 22.39 ± 0.45 cm, k = 0.46 ± 0.04 year−1, and t0 = −1.38 ± 0.13 year for males (n = 378). The growth performances of P. anomala reported from different geographic regions were compared, and the potential influences of sample size distribution on the estimated growth parameters were further discussed.

Influence of the Kuroshio path on the catches of Japanese butterfish Hyperoglyphe japonica in waters around Hachijyo-jima Island in central Japan

Influence of the Kuroshio path on the catches of Japanese butterfish <i>Hyperoglyphe japonica</i> in waters around Hachijyo-jima Island in central Japan

The present situation of utilization and the effects of artificial reefs on the resource density of Japanese butterfish &lt;i&gt;Hyperoglyphe japonica&lt;/i&gt; and red seabream &lt;i&gt;Pagrus major&lt;/i&gt; in the waters of the Iki Islands, Nagasaki, Japan

The present situation of utilization and the effects of artificial reefs on the resource density of Japanese butterfish &lt;i&gt;Hyperoglyphe japonica&lt;/i&gt; and red seabream &lt;i&gt;Pagrus major&lt;/i&gt; in the waters of the Iki Islands, Nagasaki, Japan

Growth and mortality of exploited fishes in China's coastal seas and their uses for yield-per-recruit analyses

Given the scarcity of information suitable for other forms of fish stock assessments, the growth, and mortality of 10 important marine exploited fishes in China's coastal seas were estimated, based on published length‐frequency data and the ELEFAN approach and software. The resulting parameters, complemented with growth curves from FishBase were then used for yield‐per‐recruit analyses. These 10 species were both traditional commercial species (Trichiurus lepturus, Larimichthys polyactis, Scomber japonicus) and less commercial interest species (Coilia nasus, Engraulis japonicus, Decapterus maruadsi, Psenopsis anomala, Coilia mystus, Setipinna tenuifilis, Harpadon nehereus). The yield‐per‐recruit analyses indicated that the fishing mortality experienced by these 10 fish species was very high, especially in view of the extremely small cod‐end mesh sizes deployed by Chinese trawlers, of about 10 mm or less (vs. 25 mm as minimum legal size). More precisely, all 10 species suffered from growth overfishing, which was very pronounced in large species. Indeed, enlarging cod‐end mesh size, by increasing mean sizes at first capture, would increase yield‐per‐recruit for all 10 fish species by a factor of up to 2.5. Obviously, such increases in mesh size would have to be in tandem with other management measures designed to ensure the sustainability of China's marine fisheries resources.

Seasonal changes in infection with trematode species utilizing jellyfish as hosts: evidence of transmission to definitive host fish via medusivory.

In the Seto Inland Sea of western Japan, metacercariae of three species of trematodes, Lepotrema clavatum Ozaki, 1932, Cephalolepidapedon saba Yamaguti, 1970, and Opechona olssoni (Yamaguti, 1934), were found in the mesoglea of the jellyfish Aurelia aurita s.l., Chrysaora pacifica, and Cyanea nozakii. Moreover, these jellyfish frequently harbored juveniles of the fish species Psenopsis anomala, Thamnaconus modestus, and Trachurus japonicus. The former two fish species are well-known medusivores. We investigated seasonal changes in the prevalence and intensity of these metacercariae in their host jellyfish from March 2010 to September 2012 and presumed that infection by the trematodes of the definitive host fish occurs through these associations. The mean intensity of metacercariae in A. aurita s.l. clearly showed seasonality, being consistently high in June of each year. The intensity of metacercariae in C. nozakii was highest among all jellyfish hosts and appeared to be enhanced by medusivory of this second intermediate, and/or paratenic host. Trophic interactions between jellyfish and associated fish were verified using both gut content and stable isotope analyses. The detection of trematodes and nematocysts in the guts of P. anomala and T. modestus juveniles, in addition to stable isotope analysis, suggests that transmission of the parasites occurs via prey-predator relationships. In addition, the stable isotope analysis also suggested that P. anomala is more nutritionally dependent on jellyfish than Th. modestus and Tr. japonicus.

Illumina next-generation sequencing reveals the complete mitochondrial genome of Psenopsis anomala (Perciformes: Centrolophidae) with phylogenetic consideration

Using Illumina next-generation sequencing (NGS), the complete mitochondrial genome of the Psenopsis anomala was sequenced in the present study. The mitochondrial genome of P. anomala is 16,528 bp long and consists of 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and a control region. The structure about gene order and composition of P. anomala mitochondrial genome is similar to those of most other vertebrates. The nucleotide compositions of the light strand in descending order is 29.18% of T, 27.97% of G, 27.06% of A, and 15.79% of C. With the exception of the NADH dehydrogenase subunit 6 (ND6) and eight tRNA genes, other mitochondrial genes are encoded on the heavy strand. The phylogenetic analysis by maximum-likelihood (ML) method shown that the Psenopsis anomala was closer to Peprilus triacanthus in the phylogenetic relationship.

RECENT OBSERVATIONS ON THE CHANGE OF REPRODUCTIVE TRAITS OF JAPANESE BUTTERFISH, PSENOPSIS ANOMALA, IN WATERS OFF NORTHEASTERN TAIWAN

The Japanese butterfish, 〞Psenopsis anomala〞, is one of the most important fish species for trawl fisheries in Taiwan. This species has been intensively exploited in recent decades; however, how the species adapts to this impact by changing its life history traits is poorly known. In this study, we evaluated the change in the reproductive traits of the Japanese butterfish based on samples collected 25 years apart from the waters off northeastern Taiwan. There was a significant change in the mean length of the fish caught between 1984 and 2008. The spawning season was similar for both periods, but energy reserves in the muscle and liver both decreased in 2008, especially prior to the onset of spawning. The sizes at first sexual maturity for both sexes decreased slightly, whereas the total and relative fecundities for females increased substantially. The sex ratio was skewed toward females in the pooled annual samples, as well as in most months of 1984, but this pattern was not found in 2008. It appears that 〞P. anomala〞 may compensate for the loss of population biomass by producing numerous smaller eggs and may spawn more egg batches even under lower body mass conditions. These changes are a possible response to the impact of intensive fishing pressure, which has affected not only 〞P. anomala〞 but also its prey in the ecosystem. The implications for the management of the demersal fishery resources of this region were further discussed in this study.

Mitochondrial genome of Psenopsis anomala (Pacific rudderfish) and structure schema comparison of control region in Stromateoidei

In this study, the complete mitochondrial genome of Psenopsis anomala (Perciformes, Centrolophidae) was first determined. The mitochondrial DNA was 16,509 base pairs in length. The overall base composition of P. anomala is A 28.4%, C 27.5%, G 16.6% and T 27.5%, with a slight A + T bias of 55.9%. It consists of 22 tRNA genes, 2 ribosomal RNA genes, 13 protein-coding genes and 2 main non-coding regions (the origin of the light strand replication and the putative control region), in which the genes structure and order are similar to most other vertebrates. These mitogenome sequence data would play an important role in population genetics and phylogenetic analysis of the Centrolophidae.

Performance of a conical jellyfish exclusion device installed in a trawl net

Recently, the increasing population of giant jellyfish Nemopilema nomurai has negatively affected coastal fisheries in Korea. As a result, the fishing industry has begun developing devices to prevent jellyfish capture. In this study, we assessed the performance of a conical jellyfish exclusion device in the coastal areas of Yokji Island in southern Korea during 2009. After hauling, we measured the length, diameter, and weight of the jellyfish and fish that were captured by the cod end and cover net. We found that the captured species included N. nomurai, silver croakers Pennahia argentata, yellow croakers Larimichthys polyactics, shotted halibut Eopsetta grigorjewi, largehead hairtails Trichiurus lepturus, and melon seeds Psenopsis anomala. The catch ratios of the giant jellyfish that entered the cod end in terms of weight ranged from 0.005 to 0.027. In contrast, the catch ratios of total fish in terms of weight and number were 0.793 and 0.835, respectively. On selectivity analysis of a conical separator for individual fish species, their exclusion ratios were independent of their length, and were similar to their observed exclusion ratios in terms of number. These results indicated that the conical jellyfish exclusion device performs well; however, some improvements are needed to minimize the escape of fish from the net.

Reproductive biology of the Japanese butterfish, Psenopsis anomala, in the waters off southwestern Taiwan

The dramatic decline in annual yield of the Japanese butterfish, Psenopsis anomala, in southwestern Taiwan over the past decade suggests that this stock might have been overexploited. However, its fishery biology and stock status is poorly understood. This study therefore provides the first information on P. anomala reproductive biology based on 983 specimens collected by small trawlers in southwestern Taiwan waters between February 1999 and February 2000. The sex ratio, 0.44 (431/983), differed significantly from 0.5 and females predominated in fork length above 180 mm. The relationships between body weight (BW) and fork length (FL) were estimated as BW = 1.62 A— 10−4 A— FL2.637 (r2 = 0.74; n = 430, P < 0.01) for females and BW = 1.28 A— 10−4 A— FL2.671 (r2 = 0.82; n = 552, P < 0.01) for males. Oocytes were mature at 0.5 mm in diameter or larger, and transparent eggs were found at diameters of 0.85 mm. Mean fecundity was estimated at 171 900 ± 61 700 and fecundity (F) was found to increase exponentially with gonad weight (GW) F = 5.4967GW0.511 (n = 132, r2 = 0.74). Mean batch fecundity was estimated to be 83 400 ± 44 600, and relative fecundity from 377 to 2588 (mean 1040) per gram body weight. Logistic curves describing the relationship between proportion of maturity (Pr) at each length interval and fork length were estimated as Pr = 1/(1 + e11.4194−0.0749FL) (r2 = 0.99, n = 351) for females and Pr = 1/(1 + e11.5113−0.0732FL) (r2 = 0.99, n = 258) for males. Size at 50% maturity was estimated as 15.7 and 15.3 cm FL for females and males, respectively. A multi‐spawning pattern was observed in the Japanese butterfish whereby it spawns throughout the year with a peak from February to July. A seasonal closure from April to July (spawning season for most fish species) can provide better breeding opportunities for adults and is believed to be a good fishery management measure for this species.

The catch composition of light falling-net fishing and its impact on fishery resources in the northern South China Sea.

In recent years,a light falling-net fishery was rapidly developped in the South China Sea.It has increased fishing pressure on juvenile fish resources living in the northern shallow waters of South China Sea. A survey of the catch composition of light falling-net fishing was conducted on fishing ground along waters off Yangjiang,Guangdong Province,from April 27 to May 2,2006,in order to identify catch composition of the net and its impact on fishery resources. The results showed that: (1) The main species caught were phototactic fish and cephalopod,including Loligo sp.,Trichiurus haumela,Decapterus maruadsi,Scomberomorus commerson,Psenopsis anomala,Sepia sp.,Thrissa kammalensis,Formio niger,Thryssa dussumieri and Trachurus japonicus;(2) The net had high catch rates of juveniles and might tend to damage marine fishery resources;(3) The main causes resulting in the high rates were smaller mesh size,greater light intensity and fishing ground closing to inshore. It is recommended that the regulation of the minimum mesh size be implemented and the management of the fishing gear be strengthened.

망지를 이용한 트롤 탈출장치 개발

Sea experiment for this study was carried out to develop a Trawl Escapement Net(TEN) using net material to improve the survival rate of undersized fishes that escaped from trawls in the Korean southern sea in May and November, 2005. Three kinds of Trawl Escapement Net(TEN) were examined to increase the escapement rate for fishes escaped from the TEN, and total catches in the codend and cover-net were investigated. The main catch species in the experimental fishing trials using a V shape TEN(A type) in May were Korean pomfret(Pampus echinogaster), slimy(Leiognathus nuchalis), gizzard shad(Konosirus punctatus), white croaker(Pennahia argentata) and smelt(Sillago sihama). In the experimental fishing trials using a V shape TEN with a protector for undersized fishes(B type) and a panel shape TEN with a protector(C type) in November, the main catch species were horse mackerel(Trachurus japonicus), sea pike (Sphyraena japonica), large-head hairtail(Trichiurus lepturus), kammal thryssa(Thryssa kammalensis), white croaker(Pennahia argentata), butterfish(Psenopsis anomala) and red gurnard(Lepidotrigla microptera). Most of large-sized fish species like Korean pomfret and Spanish mackerel could not escape through the TEN in the B type and C type. Catches of horse mackerel were highest in the experimental fishing of November and escapement rates for most fish species including horse mackerel were higher in the C type compared with B type.

Revision of the order Bothriocephalidea Kuchta, Scholz, Brabec &amp; Bray, 2008 (Eucestoda) with amended generic diagnoses and keys to families and genera

The tapeworm order Bothriocephalidea Kuchta, Scholz, Brabec & Bray, 2008 (Platyhelminthes: Eucestoda), which has until recently formed part of the suppressed order Pseudophyllidea, is revised. Four new genera, namely Andycestus n. g. [type- and only species A. abyssmus (Thomas, 1953) n. comb.], Plicocestus n. g. [type- and only species P. janickii (Markowski, 1971) n. comb.] (both Bothriocephalidae), Mesoechinophallus n. g. [type-species M. hyperogliphe (Tkachev, 1979) n. comb.; other species M. major (Takao, 1986) n. comb. (Echinophallidae)] and Kimocestus n. g. [type- and only species K. ceratias (Tkachev, 1979) n. comb.] (Triaenophoridae) are proposed. Parabothriocephaloides Yamaguti, 1934, Penetrocephalus Rao, 1960 and Tetracampos Wedl, 1861 are resurrected as valid genera, whereas Alloptychobothrium Yamaguti, 1968 (newly synonymised with Plicatobothrium Cable & Michaelis, 1967), Capooria Malhotra, 1985 and Coelobothrium Dollfus, 1970 (syns of Bothriocephalus Rudolphi 1808), Fissurobothrium Roitman, 1965 (syn. of Bathybothrium Lühe, 1902), Paratelemerus Gulyaev, Korotaeva & Kurochkin, 1989 (syn. of Parabothriocephaloides Yamaguti, 1934) and Tetrapapillocephalus Protasova & Mordvinova, 1986 (syn. of Oncodiscus Yamaguti, 1934) are considered to be invalid. A recently erected genus, Dactylobothrium Srivastav, Khare & Jadhav, 2006, and its type- and only species, D. choprai Srivastav, Khare & Jadhav, 2006, are considered to be unrecognisable, because their descriptions contain a number of obvious errors and also indicate that a mixture of several taxa, probably of at least two cestode orders, were studied. Parabothriocephaloides wangi nom. nov. is proposed for Parabothriocephalus psenopsis Wang, Liu & Yang, 2004 from Psenopsis anomala in China in order to avoid a secondary homonymy. All 46 genera considered to be valid are revised, with their generic diagnoses amended on the basis of a critical examination of extensive museum and newly collected specimens. Despite apparent paraphyly or polyphyly of some bothriocephalidean families, especially the Triaenophoridae, the current classification restricted to four families, proposed by Bray et al. (1994), namely the Bothriocephalidae, Echinophallidae, Philobythiidae and Triaenophoridae, is provisionally retained with slight modifications until more molecular data on most genera are available. Keys to families and genera are provided.

Ultrastructure of the tegument of the cestode Paraechinophallus japonicus (Bothriocephalidea: Echinophallidae), a parasite of the bathypelagic fish Psenopsis anomala

Abstract. The ultrastructure of the tegument in Paraechinophallus japonicus (Bothriocephalidea: Echinophallidae), a cestode parasite of the bathypelagic fish Psenopsis anomala, was studied using scanning and transmission electron microscopy. Paraechinophallus japonicus lacks a true scolex. Four different types of microtriches have been observed on the tegumental surface of P. japonicus. Capilliform (∼2.3‐μm long) and blade‐like spiniform (∼1.4‐μm long) microtriches are intermingled on the surface of the pseudoscolex. Capilliform microtriches are distinct in possessing a short base and a long electron‐lucent cap. The strobila is covered with two types of microtriches, namely filiform (∼2.1‐μm long) and tusk‐shaped microtriches (≤4.5‐μm long). Tusk‐shaped microtriches are limited to the posterior border of each proglottid and are characterized by a short and narrow base, and a large and wide, sharply pointed, electron‐dense cap. Similar tusk‐shaped microtriches were previously found in members of the family Echinophallidae and may represent an autapomorphy of echinophallid cestodes, all of them being parasitic in centrolophid fish. A unified terminology of microthrix parts is proposed.

Vitellogenesis and vitelline system in the pseudophyllidean tapeworm Paraechinophallus japonicus: ultrastructural and cytochemical studies

The vitellogenesis of Paraechinophallus japonicus (Yamaguti, 1934), the first pseudophyllidean tapeworm of the family Echinophallidae studied using transmission electron microscope, is described on the basis of ultrastructural observations of specimens from the benthopelagic fish Psenopsis anomala (Temminck et Schlegel, 1844) (Perciformes: Centrolophidae). The process of vitellogenesis in P. japonicus follows the same general pattern observed in other tapeworms. Five stages of vitellocyte development have been distinguished. The first stage corresponds to immature cells containing ribosomes and mitochondria. The second stage of development is characterized by the appearance of granular endoplasmic reticulum and Golgi complexes, formation of shell globules and lipid droplets at the periphery of the cell cytoplasm. Vitellocyte of the third stage presents accumulation of shell globules and lipid droplets. During the fourth stage, shell globule clusters are formed, and lipid droplets and rosettes of alpha-glycogen are accumulated. Mature vitelline cells are characterized by a great number of lipid droplets with glycogen in the centre of the cytoplasm, whereas shell globule clusters are situated more peripherally. The interstitial tissue of vitelline follicles of P. japonicus is syncytial with long cytoplasmic projections extending between vitelline cells. The presence of a large amount of lipid droplets in the vitelline cytoplasm within the eggs of P. japonicus may be related to egg accumulation in the uterine sac.

Frontal glands in the pseudoscolex of Paraechinophallus japonicus (Yamaguti, 1934) (Cestoda, Bothriocephalidea, Echinophallidae)

AbstractThe glands in the pseudoscolex of the echinophallid cestode Paraechinophallus japonicus (Bothriocephalidea), a parasite of the bathypelagic fish Psenopsis anomala (Perciformes, Centrolophidae), were studied using scanning and transmission electron microscopy. Two types of glands, with different morphological types of secretory granules and mechanisms for discharging their glandular secretion, were observed. Both types of gland cell bodies are localized in the parenchyma of the pseudoscolex. The syncytial glands of type I are characterized by the production of small (all ∼0.25 μm in diameter), rounded, dense secretory granules which pass though thin projections into the distal tegumental layer of the pseudoscolex. This type of gland has a unique method of discharging its secretory granules, which we call tumulogenesis. The elimination of the secretory products is realized by an encroachment of the basement membrane and underlying tegumental muscles into the surface region of the distal cytoplasm of the tegument, resulting in the formation of a ‘glandular stalk’ above which develops a superficial glandular tumulus. In the region of the glandular material of the tumulus, the basement membrane of the stalk forms a dilation, and the appearance of a membrane-bound area serves to separate the tumulus from the distal cytoplasm of the tegument. Unicellular glands of type II are characterized by large granules (0.4–0.9 μm in diameter), the presence of peripheral microtubules in the terminal region of their ducts and an eccrine mechanism for the discharge of their secretory granules. A comparative analysis of the distribution and morphology of the types of scolex glands among members of the different families of the ‘Pseudophyllidea’ (currently believed to represent two distinct orders, Bothriocephalidea and Diphyllobothriidea) is presented.