Mm In Standard Length Research Articles

First Southern Hemisphere record of the longnosed stargazer, Ichthyscopus lebeck (Actinopterygii: Perciformes: Uranoscopidae)

Two specimens (290.2 and 309.5 mm in standard length) of the longnosed stargazer, Ichthyscopus lebeck (Bloch et Schneider, 1801), were recently collected from Jakarta Bay, Jakarta, Indonesia. Described more than two centuries ago, I. lebeck has hitherto been documented exclusively from the Northern Hemisphere, encompassing the Arabian Sea, southern coastal India, the Bay of Bengal, the Andaman Sea, and Singapore. The present paper documents the first record of the species in the Southern Hemisphere. Detailed descriptions of these specimens are provided, contributing valuable insights into the characteristics of I. lebeck in the newly reported locality.

Redescription and first Japanese seamount record of Stethopristes eos (Zeiformes; Parazenidae).

During a biodiversity survey conducted in 2020, focusing on seamounts located in the southern region of Japan, specifically designated as marine protected areas, a single specimen of Stethopristes eos Gilbert, 1905 measuring 124.2 mm in standard length was obtained via the use of a remotely operated vehicle (ROV). The collection occurred at a depth of 519 meters on the Ritto Seamount, located along the western Mariana Ridge. However, this species is poorly known, with only a limited dataset available concerning its morphology. In this study, we present a comprehensive redescription of the species, utilizing information obtained from the type specimens and a newly discovered specimen from Japanese waters. The Japanese specimen constitutes the first recorded occurrence of this species within the western Pacific Ocean. As part of this redescription, we suggest new standard Japanese names for both the genus and species.

First southeastern Pacific record of Balloon Alfonsin, Beryx mollis Abe, 1959 (Beryciformes, Berycidae), with notes on geographical meristic variations

Four specimens (151–156 mm in standard length) of Beryx mollis Abe, 1959 were collected from the Nazca Ridge, southeastern Pacific Ocean. These specimens represent the first record of the species from the south-eastern Pacific Ocean and extend the distributional range of the species eastward by ca. 10,000 km from New Caledonia, the previously known eastern limit. Comparison with specimens from other regions reveals geographical variations of some meristic characters in the species.

Opistognathusctenion (Perciformes, Opistognathidae): a new jawfish from southern Japan.

Opistognathusctenionsp. nov. (Perciformes: Opistognathidae) is described on the basis of three specimens (17.3-30.6 mm in standard length) collected from the Osumi and Ryukyu islands, southern Japan in depths of 35-57 m. Although most similar to Opistognathustriops, recently described from Tonga and Vanuatu, the new species differs in mandibular pore arrangement, dorsal- and caudal-fin coloration, fewer gill rakers, and lacks blotches or stripes on the snout, suborbital region and both jaws.

Larval performance, osteological development and skeletal abnormalities in wreckfish (Polyprion americanus) under a standard rearing protocol and different light intensities and rearing temperatures

Wreckfish (Polyprion americanus) is a promising new species for aquaculture diversification due to its fast growth, late reproductive maturation, and high market price. Nowadays, low larval survival is considered the biggest limitation in wreckfish farming. Here, the fertilization, hatching and survival rates of 20 spawning events from an established wreckfish broodstock have been analyzed in order to characterize the main bottlenecks in wreckfish early and larval development. The ontogenesis of the skeletal system and the incidence of skeletal deformities have been assessed in 632 samples from larval rearing trials using currently available protocols. Furthermore, the effect of different rearing temperatures (13 vs 16 °C) and light intensities at water surface (600, 900 and 1200 lx) on the skeletal development have been also explored. Results showed as while a variable egg fertilization rate (61.75 ± 34.62%) were achieved, a very poor hatching (4.52 ± 9.27%) and survival rate (0.01 ± 0.00%) until 71 days post hatching (dph) were observed. Swim bladder inflation was first seen at 7 dph, and at 11 and 25 dph a 61–63% of fish functional swim bladder. The first skeletal structures to be formed were those related with breathing and feeding activities (e.g., cleithrum, Meckel's cartilage and ceratobranchials) and were visible in larvae of 4–5 mm of standard length (SL). Ossification of the vertebral column progressed in an anterior-to-posterior direction, being fully ossified at 7–14 mm of SL. Regarding the skeletal deformities, a high incidence (63%) of jaw deformity (particularly lower jaw deformity) was observed in larvae of 4–5 mm of SL, progressively decreasing (up to 5%) in larvae of >6 mm of SL. Deformed vertebrae (compressed, fused, and/or displaced) were mainly located at 13 to 15th vertebra, and were associated to lordosis, most probably due to the no swim bladder inflation. No clear relationship between temperature and the incidence of lower jaw deformity was observed during endotrophic larval development. Light intensity had a clear effect on survival but not in skeletal development. Larvae reared under 600 lx had lower survival (0.15 ± 0.21%) at 21 dph than when reared with 900 and 1200 lx (0.6 ± 0.28 and 0.7 ± 0.28%, respectively). The present research work represents an important step forward to solve wreckfish larval rearing bottlenecks, suggesting that while temperature and light intensity might have an effect on wreckfish larval survival and development, egg quality and incubation seemed to be the most limiting factors for successful wreckfish aquaculture.

Advancements in hatchery production of red snapper Lutjanus campechanus: Exclusive use of small strain rotifers as initial prey for larval rearing

AbstractThe red snapper (Lutjanus campechanus) has one of the most valued fisheries in the southeastern United States and has been largely studied for its aquaculture potential with varied results that revealed production challenges. This study focused on addressing challenges in larval rearing and juvenile production of this species. Broodstock fish were acclimated in a 60 m3 tank equipped with recirculating aquaculture system (RAS) and temperature control. After 1 year in captivity, fish volitionally spawned and larval rearing trials were conducted in replicated flow‐through seawater tanks ranging from 0.4 to 2.4 m3, at a temperature range of 24–26°C. Enriched s‐strain rotifers, Brachionus rotundiformis (lorica length of 100–210 μm), were used for first feeding. Enriched Artemia sp. were gradually introduced after 18 days post hatch (DPH). The survival rate before metamorphosis (12 DPH) averaged 66.09 ± 0.08%. Survival rate from yolk‐sac larvae to post‐metamorphic early juvenile averaged 4.43 ± 0.01%. At 40 DPH, early red snapper juveniles averaged 0.35 ± 0.02 g in weight and 28.83 ± 0.60 mm in standard length. A total of 31,849 fully weaned juveniles were harvested. This study demonstrates that small strain rotifers can be used exclusively as first feeding prey organism for red snapper larvae, representing a significant advancement for red snapper juvenile production.

Description of a New Deep-Water Eulophiid Fish (Perciformes: Zoarcoidei) from Japan

The genus Eulophias, which is an enigmatic group of the suborder Zoarcoidei, previously comprised two rare species: Eulophias tanneri Smith, 1902 (type species and a senior synonym of Eulophias owashii Okada and Suzuki, 1954) and Eulophias koreanus Kwun and Kim, 2012. Here we describe a new species, Eulophias spinosior, based on 71 specimens (94.9–182.3 mm in standard length, SL) collected from the upper slope of the northwestern Pacific off southern Japan at depths of 257–555 m. It readily differs from its two congeners in having 133–143 dorsal-fin spines, 109–116 anal-fin soft rays, 5–6 pectoral-fin rays, and 146–156 total vertebrae, and in lacking a dark band posterior to the eye and a series of dark blotches midlaterally on the trunk and tail. Regarding bathymetric distribution, the new species occurs much deeper than E. koreanus and E. tanneri. Eulophias spinosior, new species, is sexually dimorphic, with males having large, stout, modified canines at the tips of the premaxillary and dentary (vs. only slightly enlarged in females). Dentition of males also differs from that of females in that most teeth are uniserially arranged in each jaw (vs. distinct two rows anteriorly).

First Specimen-based Japanese Records of the Barred Queenfish <i>Scomberoides tala</i> (Teleostei: Carangidae) from Miyazaki and Okinawa Prefectures, Southern Japan

Two specimens of the carangid fish Scomberoides tala (Cuvier, 1832) (141.5–411.0 mm in standard length, 151.9–433.0 mm in fork length), collected from northern Miyazaki Prefecture and the Yaeyama Islands, southern Japan, represent the first specimen-supported Japanese records and northernmost record of the species, previously recorded from the east coast of South Africa, Arabian Sea, Bay of Bengal, Indo-Australian Archipelago, Australia, Gulf of Thailand, and South China Sea. In addition, the distribution of S. tala in Japanese waters was assessed on the basis of a previous photographic record, and the Japanese name for the species was discussed.

Nuevos registros y datos morfométricos y merísticos del conejo de hondura, Sphoeroides pachygaster (Tetraodontiformes: Tetraodontidae), en el suroeste del golfo de México

The objective of this contribution is to present new records of the occurrence of Sphoeroides pachygaster, based on 8 specimens deposited in a scientific collection of 175-313 mm in standard length weighing 178.7-1 010 g, which were captured south of Veracruz, southwestern Gulf of Mexico. In addition, meristic and morphometric data of the captured specimens are given and discussed as support for identification.

First specimen-based Indonesian record of a rare scorpionfish, Scorpaenopsis obtusa (Actinopterygii: Perciformes: Scorpaenidae), from Alor Island

A single specimen of the shortsnout scorpionfish, Scorpaenopsis obtusa Randall et Eschmeyer, 2002 (Scorpaenidae), collected from the south coast of Ampera, Alor Barat Laut, Alor Island, Indonesia, at 5 m depth, represents the first voucher specimen-supported record of the species from Indonesian waters (previous records from Nusa Penida and northern Sulawesi having being based on underwater photographs). At 91.1 mm in standard length, the Alor specimen is the largest recorded individual of the species to date.

Larval study revealed diversity and life-history traits of crypto-benthic eel gobies.

Because adult and juvenile eel gobies usually hide within the burrows of muddy substrates, their diversity and life history have not yet been fully elucidated. We investigated larval specimens of the eel gobies collected on Okinawa Island in southern Japan. The genus Trypauchenopsis was previously thought to consist of only one species, but our larval collection identified two species, Trypauchenopsis limicola and Trypauchenopsis intermedia, distinguished by their species-specific melanophore arrangements and differences in their fin-ray counts. Taenioides kentalleni were previously known from only two specimens worldwide. A third specimen of this species has now been added from the larval collection. In addition to the three species above, Taenioides gracilis and Caragobius urolepis were identified and the larval morphologies of the five species were described for the first time. All the larvae collected in the present study were at late postflexion stage. T. limicola, T. intermedia and T. gracilis were presumably collected in the estuaries and beaches when approaching their adult habitats at the end of pelagic life. They were 8.5-10.3 mm in standard length, and otolith analysis suggests that their pelagic larval durations are a little longer than 1month (average 34-37 days). The larval occurrence suggested that the spawning season of T. limicola is May-December, when the water temperature is warmer than approximately 20°C. Our work reveals that studying the larval stage can provide new information on the taxonomy and life history of the elusive cryptobenthic fish.

Owstonia aurora (Perciformes: Cepolidae: Owstoniinae), a new bandfish from the Philippines

Owstonia aurora sp. nov. is described on the base of three specimens (69.8-88.0 mm in standard length) collected off East Luzon during the "Aurora 2007" Philippine Expedition. The new species differs from its congeners by the following combination of characters: dorsal-fin elements III, 21; anal-fin elements I, 14; gill rakers on first arch 35-38; cheek with 80-86 scales in 7-8 rows; lateral line without branch, not forming loop in front of dorsal-fin, ending below 17th to 22th dorsal-fin soft rays; oblique body scale rows in mid-lateral series 54-58; lower margin of preopercle rounded; prominent black blotch on anterior dorsal-fin membrane, and extend downward to dorsal-fin base, remaining membrane of dorsal, anal, and caudal fins red with white margins and bases, distinct white stripes on mid dorsal and caudal fin membranes; membranes between maxillary and premaxillary with discontinuous black stripes or patches.

First report of crested cusk-eel, Ophidion josephi (Actinopterygii: Ophidiiformes: Ophidiidae), in the southwestern Gulf of Mexico

The crested cusk-eel,Ophidion josephiGirard, 1858, is a coastal marine species that is distributed in the northwestern Atlantic, from the northern Gulf of Mexico to Georgia, USA. Eighteen specimens (177–230 mm in standard length) were caught by beach purse seine at a depth of about 5 m, in Veracruz, in the southwestern Gulf of Mexico. This is the first documentation from Mexican marine waters and the southernmost confirmed records of this species, showing that its range extends further south than previously known and that it shares faunistic similarities with other species in the northwestern Atlantic.

First Specimen-based Records of Redfin Emperor <i>Monotaxis heterodon</i> (Perciformes: Lethrinidae) from Japan, with New Diagnostic Characters Applicable to Identification of Preserved Specimens

Twenty-four specimens (184.6–243.6 mm in standard length) of Monotaxis Anonymous [Bennett], 1830, collected from the Ryukyu Islands, southern Japan, were identified as M. heterodon (Bleeker, 1854) (Perciformes: Lethrinidae). Although a widely distributed Indo-West Pacific species, all previous records from Japanese waters have been based solely on photographs, the present specimens therefore representing the first specimen-based records of M. heterodon from Japan. A detailed comparison between M. heterodon and its only congener, M. grandoculis (Forsskål, 1775), from which it has previously been distinguished primarily by scale rows below the lateral line and fresh or live coloration, revealed new diagnostic characters, most of which are applicable to preserved specimens. In addition to previously recognized characters, the two species can be distinguished by mid-dorsal snout profile in adults (concave vs. straight), snout length (excluding lips) [8.9–11.1 (mean 9.9) % of SL vs. 10.3–12.1 (11.2) % SL], spinous anal-fin base length [4.6–5.9 (5.0) % of SL vs. 3.9–4.9 (4.4) % SL], a distinct black blotch above the pupil (absent vs. present), a dark brown stripe across the post interorbital region in preserved specimens (present vs. absent), and preserved coloration of the pectoral-fin base inner surface (blackish brown vs. light brown).

Reproductive ecology and adaptive host choice correlated with body size in an autumn-spawning bitterling Acheilognathus typus.

The life history and reproductive ecology of an autumn-spawning bitterling Acheilognathus typus were studied under natural and experimental conditions. In the study pond, the embryos of A. typus emerged from mussels in May and grew rapidly until August, whereas overwintered age-1 fish grew slowly. Adult A. typus in the pond was smaller (32-47 mm in standard length) than they were in other habitats and mainly spawned in smaller mussels. The number of A. typus embryos in mussels was negatively correlated with the shell length of the mussel, and a lower number of embryos were observed in larger mussels (over 110 mm in shell length). In the mussel size-choice experiment conducted in an enclosure, smaller A. typus selected smaller mussels, and larger A. typus selected larger mussels for spawning. In some cases, smaller A. typus spawned in larger mussels and the number of spawned eggs ejected increased by over four times compared with other cases. These results of the enclosure experiment explained the lower number of embryos in larger mussels in the study pond. In addition, reproductive traits such as ovipositor length and the number of ovulated eggs of female A. typus, which are considered to contribute to their size-dependent host utilization, were positively correlated with their standard length. Because A. typus is geologically or seasonally isolated from other bitterling species, this size-dependent host utilization contributes to a reduction in intraspecies rather than interspecies competition.

Estimated richness and environmental correlates of miniature fish assemblages in the rio Jacundá, Brazil

Abstract South America is home to more miniature fishes (<26 mm in standard length) than any other continent. Despite this diversity, the ecology of miniature fishes is poorly studied. To promote the study of miniature fish ecology, we investigated patterns in total richness, assemblage structure and environmental correlates for miniature fishes in the rio Jacundá drainage of the Lower Amazon River basin, Pará State. Based on multi-pass dip-netting of leaf litter at 20 locations distributed across two sites, we collected miniature species and used rarefaction to estimate 9 to 14 species might be present. The miniature fish assemblage at the upstream site was a nested subset of the downstream site, and water pH and canopy cover, two features known to be altered by deforestation, correlated most strongly with assemblage variation. Our work represents one of the first quantitative assessments of environmental correlates with miniature fish assemblages and highlights research topics that should be investigated further to promote conservation and preservation of the overlooked and understudied Amazonian diminutive freshwater fish fauna.

Osteology of Tucanoichthys tucano Géry and Römer, an enigmatic miniature fish from the Amazon basin, Brazil (Teleostei: Characiformes: Characidae)

Miniaturization, the evolution of extremely small adult body size, is a common phenomenon across the lineages of freshwater fishes, especially in the Neotropics where over 200 species are considered miniature (≤26 mm in standard length [SL]). Close to 30% of all miniature Neotropical freshwater fishes belong to the family Characidae, several of which are of uncertain phylogenetic placement within the family. We investigate the skeletal anatomy ofTucanoichthys tucano, a species of uncertain phylogenetic position from the upper Rio Negro basin, reaching a maximum known size of 16.6 mm SL. The skeleton ofTucanoichthysis characterized by the complete absence of ten skeletal elements and marked reduction in size and/or complexity of others, especially those elements associated with the cephalic latero-sensory canal system. Missing elements in the skeleton ofTucanoichthysinclude those that develop relatively late in the ossification sequence of the non-miniature characiformSalminus brasiliensis, suggesting that their absence inTucanoichthyscan be explained by a simple scenario of developmental truncation. A number of the reductions in the skeleton ofTucanoichthysare shared with other miniature characiforms, most notably species ofPriocharaxandTyttobrycon, the latter a putative close relative ofTucanoichthysbased on molecular data.

Callogobius falx, a new species of goby from southern Japan.

Callogobius falx n. sp. (Gobiidae) is described on the basis of two specimens (14.4 and 23.1 mm in standard length: SL) from the Ryukyu Islands, southern Japan. The new species is characterized by the following combination of characters: dorsal-fin rays VI-I, 8 or 9; anal-fin rays I, 7; pectoral-fin rays 18 or 19; lateral scale rows 2022; body depth moderate, neither particularly slender nor deep (depth at pelvic-fin origin 18.320.0% of SL); pelvic-fin base with frenum; caudal-fin length moderate, margin rounded; cephalic sensory-canal pores absent; interorbital papillae row separated, forming two rows (one row in 14.4 mm paratype); postorbital papillae row not continuous with upper cranial papillae row; preopercular and transverse opercular papillae rows connected, forming single transverse row; body with three oblique black bars, angled upwards anteriorly and continuous with black bars on dorsal fins, anteriormost bar extending from 1st dorsal fin to midline of body, posterior two bars extending from second dorsal fin to dorsal surface of body and caudal peduncle, respectively; pectoral fin white, upper half widely (ca. 1/2 length of rays) margined with black; caudal-fin base with narrow sickle-like bar.

New record of white-spotted pufferfish Arothron hispidus (Linnaeus, 1758) (Tetraodontiformes: Tetraodontidae) from West Bengal, India, compared with other Arothron species occurring in India

Two specimens of Arothron hispidus (Linnaeus, 1758) (111.7 – 112.8 mm in standard length), was collected in May 2019 from the Frasergunj fishing harbour in West Bengal, eastern India. Herein, we report this species for the first time from West Bengal. We have described the diagnostic features of the collected specimens and compared them with other Arothron species found in Indian waters.

Use of archaeological data in retracing diet and growth of extirpated fish populations in the California Delta: An allometric and isotopic approach to Sacramento perch (Archoplites interruptus) historical ecology

Sacramento perch (Archoplites interruptus), ubiquitous in the archaeological record throughout Central California, is now extirpated from the California Delta. Descriptions of Sacramento perch ecology, biology, and behaviour are either from relocated or declining populations. Archaeological specimens have the potential to provide insight on Sacramento perch demographics and feeding behaviour in their native range prior to large scale damming and the introduction of invasive species. We develop regression formulae to predict live length for three skeletal elements (vomer, dentary, and atlas). Formulae were applied to archaeological specimens (n = 182) from CA-CCO-647 (cal CE 1230–1440), Contra Costa County, California. Archaeological samples were then compared to length data from six contemporary relocated populations. Bulk collagen samples of specimens of varying lengths (n = 12) were run for δ13C and δ15N. Archaeological specimens averaged 196 mm in standard length, and attained longer average and maximum lengths than relocated perch populations. Length distributions showed a high proportion of newly sexually mature individuals, suggesting that Sacramento perch were targeted while spawning nearshore. Nitrogen values correlated positively with standard length, suggesting that within the California Delta, Sacramento perch feeding behaviour changed as individuals grew, likely marking a shift to more piscivorous diets with age. Data highlight the potential of archaeological assemblages in reconstructing past length distributions and feeding behaviour for extirpated fish populations in their endemic ranges.