Fin Ray Counts Research Articles

Morphometric and meristic variation in two congeneric archer fishes Toxotes chatareus (Hamilton 1822) and Toxotes jaculatrix (Pallas 1767) inhabiting Malaysian coastal waters

A simple yet useful criterion based on external markings and/or number of dorsal spines is currently used to differentiate two congeneric archer fish species Toxotes chatareus and Toxotes jaculatrix. Here we investigate other morphometric and meristic characters that can also be used to differentiate these two species. Principal component and/or discriminant functions revealed that meristic characters were highly correlated with pectoral fin ray count, number of lateral line scales, as well as number of anal fin rays. The results indicate that T. chatareus can be distinguished from T. jaculatrix by having a greater number of lateral line scales, a lower number of pectoral fin rays, and a higher number of anal fin rays. In contrast, morphometric discriminant analyses gave relatively low distinction: 76.1% of fish were ascribed to the correct species cluster. The observed morphometric differences came from the dorsal and anal spines lengths, with T. chatareus having shorter dorsal and longer anal spines than T. jaculatrix. Overall, meristic traits were more useful than morphometrics in differentiating the two species; nevertheless, meristics and morphometrics together provide information about the morphological differentiation between these two closely related archer fishes.

Redescription of the Tyee Sucker,Catostomus tsiltcoosensis(Catostomidae)

ABSTRACT. We resurrect Catostomus tsiltcoosensis, the Tyee sucker of Oregon coastal rivers, from the synonymy of Catostomus macrocheilus and compare it with its congeners. Catostomus tsiltcoosensis is superficially similar to disjunctly distributed Catostomus occidentalis of the Sacramento drainage and Catostomus ardens of the Upper Snake River and Bonneville Basin. However, the gill raker structure, wide frontoparietal fontanelle, location of the ninth cranial foramen, scale radii patterns, and cytochrome b sequences clearly align C. tsiltcoosensis with C. macrocheilus rather than C. occidentalis. Differences in counts of infraorbital pores and dorsal fin rays, in body depth proportions, and in cytochrome b sequences distinguish C. tsiltcoosensis and C. macrocheilus. Within C. tsiltcoosensis, specimens from each of the 4 main drainages (north to south—Siuslaw, Umpqua, Coos, and Coquille) were reciprocally monophyletic based on cytochrome b data but showed no differences in the morphological features exam...

A larva of Coryphaenoides pectoralis (Gadiformes: Macrouridae) collected by deep-sea submersible from off Hokkaido, Japan

A late-stage larva of Coryphaenoides pectoralis was first observed in situ and subsequently collected by the deep-sea submersible “Shinkai 2000” from mesopelagic waters at a depth of 530 m off Hokkaido, Japan. The larva (14.5 mm in head length, 149+ mm in total length) has fan-like pectoral fins, elongate first dorsal fin, pelvic fin and tail, 10 first dorsal rays (including 2 pseudospines), and 7 pelvic fin rays, 6 branchiostegal rays, no light organ, anus just anterior to anal fin origin, 2 retia and gas glands, 14 abdominal vertebrae, and previously reported larval pigmentation. Counts of second dorsal and anal fin rays, and caudal vertebrae, are reported for the first time.

Development of Eggs, Larvae and Juveniles of the Puffer, Takifugu chrysops, Reared in the Laboratory

The artificial fertilization of the puffer,Takifugu chrysops (Hilgendorf), was carried out at Sajima in Yokosuka City on May 22, 1984. Hatched larvae were reared for a period of about 150 days. The spawning period seems to extend from mid to late May in the eastern part of Sagami Bay. The eggs were spherical, pale milky white and semitransparent, demersal and adhesive in nature, measuring 1.32±0.04 mm in diamter, and with a cluster of small oil-globules. The incubation period was about 162 hours at a water temperature of 17.4 to 21.8°C. During embryonic development, the only pigment cells that appeared on the embryo were the black chromatophores. The newly hatched larvae measured from 2.72 to 3.06 mm TL, averaging 2.87±0.1 mm TL, and 22–23 (9 + 13−14) myomeres. At yolk absorption, 4 days after hatching, the larvae attained 3.64–3.79 mm TL. On the 11th day, postlarvae averaged 4.69±0.24 mm TL. Larval finfolds disappeared and rudimental dorsal, anal and caudal fins were formed. There were two large clusters of melanophores, one on the back, exteding from the mid-base of the dorsal fin to the caudal peduncle region, the other along the anal fin base. The color of the body began to turn pale green to brownish-orange and spinelike scales appeared on the belly. Eighteen days after hatching (7.02±0.27 mm TL), the caudal notochord began to turn up and a “constriction” appeared on the posterior margin of the caudal fin membrane. This notch moved upwards as the notochord upturning advances. The larvae attained full fin ray counts and reached the juvenile stage at 9.1-9.5 mm TL, 24 days after hatching. Characteristic black blotches on the back and specific brownish orange body color appeared at the stage of 20 mm TL, 24 days after hatching.

Triso, a new generic name for the serranid fish previously known as Trisotropis dermopterus, with comments on its relationships

The generic nameTriso is proposed for the epinephelin fish recent authors have identified asTrisotropis dermopterus (Temminck et Schlegel).Trisotropis Gill is a junior synonym ofMycteroperca Gill.Triso is distinctive in its short head, broad interorbital, foreshortened neurocranium, anteriorly inclined parasphenoid, high and laterally oriented frontoparietal crests, high dorsal fin-ray counts, and pouch-like esophageal swellings.Altiserranus woorei Whitley from New South Wales is placed in the synonymy ofT. dermopterus. Altiserranus Whitley, type speciesEpinephelus multinotatus (Peters), is synonymized withEpinephelus Bloch.T. dermopterus occurs in the Northern Hemisphere off Japan, Korea, Taiwan, and China, and in the Southern Hemisphere off eastern and western Australia; thus it is antitropical in distribution. Available evidence indicates thatTriso may be most closely related to the New World genusParanthias Guichenot.

The characteristics of the moonfish, <i>Citharinus citharus</i> (Eoffroy–St Hilaire, 1809) of Lake Oguta, Nigeria

Aquaculture holds the highest prospect for increased fish production in Nigeria and can only thrive if proven culturable fishes are available and diversified. This has necessitated the characterization of non-conventional culturable species, which abound in the wild. An example of such fish with very high potential for culture purposes is Citharinus citharus of Lake Oguta. The present study therefore investigates the identity of the fish using the morpho-meristic analysis method. All the important diagnostic features evaluated conformed to the values recorded and features described for C. Citharus of the region (Upper Niger). Of particular importance for field identification of fingerlings for culture purposes are the number of scales between the lateral line and the pelvic fin (lower transverse series), which was 17-20 and number of scales in the longitudinal (lateral line) series, 81-92; fin ray counts are as fellows: Div-vi, 14-15 and A iii – iv, 23-27. It is hoped that the resulting information will assist fish farmers in procuring seed of this fish from the wild and will serve for the general development of aquaculture in Nigeria.

A review of vertebral and fin-ray counts in the genus Alburnoides (Teleostei: Cyprinidae) with a description of six new species

Variations in the different vertebral patterns and unpaired fin counts in the genus Alburnoides are discussed based on an examination of over 1100 specimens from a wide area of distribution of the genus. Though it was commonly considered that the morphological differences between subspecies and local forms of A. bipunctatus auctorum appear slight, our study shows that there are pronounced differences between many of them in vertebral and dorsal and anal fin counts. To estimate reliability of differences, statistical tests were used and a cluster analysis (UPGMA - Average Linkage clustering method) was performed based on calculated values, and tree diagrams are presented and analyzed in their taxonomic context. The differences in fin ray and vertebral counts in combination with some other morphological characters, distinguished some of the former subspecies or local forms as distinct species. Along with five nominal taxa re-established to a species level (A. rossicus, A. kubanicus, A. maculatus, A. eichwaldii, A. fasciatus), we describe six new species: A. gmelini (type locality Sunzha River, Terek River drainage, Eastern Ciscaucasia, Russia), A. varentsovi (type locality Ashkhabadka River, northern slope of the Kopetdag, Turkmenistan), A. petrubanarescui (type locality Qasemlou Chay, Orumiyeh Lake basin, Iran), A. namaki (type locality qanat at Taveh, Namak Lake basin, Iran), A. nicolausi (type locality Simareh River in Karkheh River system, Tigris River drainage, Iran), and A. idignensis (type locality Bid Sorkh River, Gav Masiab River system, Tigris River drainage, Iran).

Morphological development of larval and juvenile blacktip grouper, Epinephelus fasciatus

The morphological development of larval and juvenile blacktip grouper, Epinephelus fasciatus, was examined using a hatchery-reared series. By about 5 mm body length (BL), the larvae developed characteristic pigmentation patterns of groupers, such as melanophores on the dorsal part of the gut, on the tips of the second-dorsal and pelvic fin spines, and on the midpoint of the tail to form a cluster. In addition, characteristic spines of groupers, such as spinelets on the second-dorsal and pelvic fin spines, and the preopercular angle spine developed by about 6 mm BL. The notochord end was in the process of flexion in larvae of 6–7 mm BL, by when major melanophores, spines, and jaw teeth started to appear. After the fin ray counts attained the adult complement at about 14 mm BL, somewhat densely pigmented bands started to appear on the body. The fish had the five distinct transverse bands and attained adult-like attire at about 40 mm BL when the major head spines disappeared and body parts in relation to BL became stable.

Description of three new species of Glossogobius from Australia and New Guinea

The present paper describes two new species of the gobiid fish genus Glossogobius from southern New Guinea and a third related species from northeastern Australia. All three species are restricted to a small number of river systems. Glossogobius bellendenensis, sp. nov. is distinctive in having reduced predorsal scales and fin-ray counts and mental frenum shape. It is restricted to relatively clear water rivers of northeastern Queensland. The closely related, Glossogobius muscorum sp. nov. is also distinctive in reduced predorsal scales and fin-ray count and is found only in the Fly River system of New Guinea. Glossogobius robertsi sp. nov. is distinctive in fin-ray and scale counts and is found in the Fly River in Papua New Guinea and possibly in a river in Papua close to the Fly River. That species has been confused with Glossogobius giuris, which generally occurs in lower reaches of the river.

Review of the Dinematichthyini (Teleostei: Bythitidae) of the Indo-west Pacific.Part IV. 'Dinematichthys' and two new genera with descriptions of nine new species

A revision of the dinematichthyine fishes (Ophidiiformes: Bythitidae: Brosmophycinae) of the Indo-West Pacific based on more than 6500 specimens is published in several parts. Part IV is the last part and includes 4719 identified specimens in the genera 'Alionematichthys' (new genus with three described and eight new species), 'Dinematichthys' Bleeker, 1855 (with one described and one new species) and Porocephalichthys (new genus with one described species). A neotype of 'Dinematichthys iluocoeteoides' Bleeker, 1855 is here designated. The genera reviewed here have in common a high anterior nostril and are considered to be related to each other. When previously described, they were all included in the genus 'Dinematichthys'. The separating characters of the species are the pseudoclasper morphology, morphometric characters, vertebrae and fin ray counts, otolith morphology, head squamation, presence or absence of the upper preopercular pore and development of cirri on the snout.

Description of early ontogeny and osteological development of streaked mojarra Eugerres lineatus (Teleostei: Percoidei: Gerreidae)

Embryos, larvae, and juveniles of the streaked mojarra Eugerres lineatus are described and illustrated from a series of laboratory specimens. The description was based on morphometry, pigmentation pattern, squamation sequence, and osteological development. The eggs were obtained by stripping ripe adults captured in Bahía de La Paz, Baja California Sur, México. Eggs (cleavage egg and embryo phases) had a mean diameter of 0.69 mm with an oil globule of 0.19 mm mean diameter. Eleutheroembryos were 1.05 mm mean notochordal length (NL) at hatching. The yolk sac was absorbed by 2.10 mm mean NL, underwent notochord flexion at 3.16 mm NL-3.86 mm standard length (SL), and transformed to juveniles at 10.0 mm SL. Juveniles were completely scaled by 14.0 mm SL. Osteological development of the neurocranium, jaws and suspensorium, opercular series, hyoid and branchial arches, vertebral column and ribs, and the paired and unpaired fins and the supports were studied. The identification of the earliest stages of development of E. lineatus compared to the other gerreids and allied taxonomic groups present along the northwestern Mexican coast is possible only in the juvenile period (24.1 mm SL), based on anal fin ray count (II, 9-III, 8), the presence of papilliform teeth, and the number of gillrakers on the lower first pharyngeal arch (15–20).

A new snailfish, Paraliparis nigellus sp. nov. (Scorpaeniformes, Liparidae), from the northern Mid-Atlantic Ridge – with notes on occurrence of Psednos in the area

During the international MAR-ECO cruise with R/V G.O. Sars in June and July 2004, among the other topics focusing on the ichthyofauna of the northern Mid-Atlantic Ridge, three specimens of the snailfish genus Paraliparis Collett, 1879 were collected in two bottom trawl hauls at 42 and 51°N, at depths 1950 and 2107 m. The specimens of Paraliparis are a new species, most similar to the P. copei complex. Paraliparis nigellus sp. nov. differs from other members of this group in number of vertebrae, dorsal fin ray counts and body color. In addition, three specimens of Psednos groenlandicus Chernova were collected. Together, they represent the first identified records of Liparidae from the northern part of the Mid-Atlantic Ridge.

First record of the pacific fanfishpteraclis aesticola (jordan and snyder, 1901) in the tropical eastern pacific

One specimen ofPteraclis aesticola was collected off San Jose del Cabo, Baja California Sur, Mexico (22°54′N, 109°45′W), in March 2007. Present record is the first reported occurrence of the species in the Tropical Eastern Pacific biogeographic region (Gulf of California to southern Ecuadorian waters). Its large fan-like anal and dorsal fins and its counts of fin rays and vertebrae can distinguish the Pacific fanfish from the other species in the genus. This fish may have not yet been recorded in the region because its presence has been overlooked in the past because of rarity and lack of commercial value.

Identification of Albula sp. (Albulidae: Albuliformes) Leptocephalus Collected from the Southern Coastal Waters of Korea using Cytochrome b DNA Sequences

A single specimen ofAlbula leptocephalus (55.7 mm SL) was collected from the southern coastal waters of Korea using an aquatic lamp. It is characterized by having a ribbonlike body with a small head and a well-forked caudal fin. Although the general appearance was similar to the leptocephalus ofA. vulpes including myomere counts and fin ray counts, the melanophore deposition was different from that ofA. vulpes. This leptocephalus specimen was confirmed withA. forsteri using the cytochrome b mtDNA (Cytb) analysis. The genetic distance ofCytb between the present leptocephalus andA. forsteri is 0.006-0.038, which falls into the cutoff point separatingAlbula species into eight deep lineages including the four valid species. Its genetic characteristic have more similarities to those of Fiji than those of Hawaii and the Northern territory of Australia.

Occurrence and morphology of larvae and juveniles of six Luciogobius species from Aritsu Beach, Okinawa Island

Larvae and juveniles of six species of Luciogobius were collected at Aritsu Beach on Okinawa Island using a small seine. Postflexion larvae were dominant during sampling and were collected when they approached the shoreline adjacent to or at the entrances to their adult habitats prior to settlement. Standard lengths of postflexion larvae ranged from 5.4 to 14.4 mm and varied depending on the species. The larvae occurred mainly from January to April, but some larvae were caught in October and November. Their pelagic larval durations were estimated to range from 17 to 36 days and varied depending on the species. Morphologies of field-caught larvae and juveniles and laboratory-reared juveniles were described. Six species were clearly distinguished based on fin ray and vertebral counts, proportions, body size, and pigment patterns. Although their taxonomic statuses could not be determined, it is thought that they have independent relatives in other regions.

Differences in meristic counts of the genus <i>Clarias</i> (pisces: clariidae) in Anambra river, Nigeria

Specific differences in meristic counts were exhibited in both the anal fin ray count and the vertebral count in the clariids of Anambra rver, Nigeria. There was a close numerical relationship between the number of anal fin rays and the number of vertebrae. The present study further justifies the taxonomic importance of anal fin ray count in differentiating Clarias species. Keywords: Meristic Counts, Clarias, Clariidae, Anambra River Animal Research International Vol. 1 (1) 2004: pp. 31-35

Comparison of genetic diversity at microsatellite loci and quantitative traits in hatchery populations of Japanese flounder Paralichthys olivaceus

Relationships of genetic diversity at microsatellite loci and quantitative traits were examined in hatchery‐produced populations of Japanese flounder using a relatively straightforward experiment. Five hatchery populations produced by wild‐caught and domesticated broodstocks were used to examine the effects of different levels (one to three generations) of domestication on the genetic characteristics of hatchery populations. Allelic richness at seven microsatellite loci in all hatchery populations was lower than that in a wild population. Genetic variation measured by allelic richness and heterozygosity tended to decrease with an increase in generations of domestication. In addition, the degree of genetic differentiation from a wild population increased with an increase in generations of domestication. Significant differences in three morphometric traits (dorsal and anal fin ray counts and vertebral counts) and three physiological traits (high temperature, salinity and formalin tolerance) were observed among the hatchery populations. The degree of phenotypic difference among populations was larger in morphometric traits than in physiological traits. The divergence pattern of some quantitative traits was similar to that observed at microsatellite loci, suggesting that domestication causes the decrease of genetic variation and the increase of genetic differentiation for some quantitative traits concomitantly with those for microsatellite loci. Significant positive correlation was observed between FST and the degree of phenotypic difference in the three morphometric traits and formalin tolerance, indicating that genetic variation at microsatellite loci predicts the degree of phenotypic divergence in some quantitative traits.

FIN-RAY COUNT VARIATION IN 0-GROUP FLATFISH: PLAICE (<i>PLEURONECTES PLATESSA</i> (L.)) AND FLOUNDER (<i>PLATICHTHYS FLESUS</i> L.) ON THE WEST COAST OF IRELAND

During the autumns of 2005 and 2006, 0-group plaice (Pleuronectes platessa (Linnaeus)) and flounder (Platichthys flesus Linnaeus) were collected from beaches in Galway and Kerry on the west coast of Ireland by beach seining and push netting. Characteristics used to identify adult flatfish were not discernible in these juveniles, and fin-ray counts were used to differentiate between the species. The dorsal, anal and caudal rays of 325 plaice and 116 flounder were counted and plotted, resulting in a clear separation between the two species. Thus, fin-ray counts may be used to reliably separate these two species on the west coast of Ireland. The ranges observed for both species lie within those previously reported. Analysis of fin-ray counts for both plaice and flounder showed no significant difference between the two regions studied. However, for plaice, a significant difference in dorsal fin-ray numbers was observed between the Galway beaches. No evidence of plaice/flounder hybrids, as identified by intermediate ray counts, was observed. There was no relationship between the numbers of dorsal and anal fin rays for plaice. However, a positive relationship was found between the numbers of dorsal and anal rays for flounder.

Review of the dinematichthyini (Teleostei: Bythitidae) of the Indo-west Pacific. Part III. 'Beaglichthys, Brosmolus, Monothrix' and eight new genera with description of 20 new species

An ongoing revision of the dinematichthyine fishes (Ophidiiformes, Bythitidae, Brosmophycinae) of the Indo-west Pacific based on ca. 5000 specimens is published in several parts. Part III includes 957 identified specimens in the genera Beaglichthys Machida, 1993 (with one described and two new species), Brosmolus Machida, 1993 (with one described species), Dactylosurculus (new genus with one new species), Didymothallus (new genus with one described and two new species), Eusurculus (new genus with three new species), Lapitaichthys (new genus with one new species), Majungaichthys (new genus with one new species), Mascarenichthys (new genus with two new species), Monothrix Ogilby, 1897 (with one described species), Ungusurculus (new genus with six new species) and Zephyrichthys (new genus with one new species). In addition, a third new species is described of the genus Paradiancistrus Schwarzhans, M ller and Nielsen, 2005, which had been established in part I of the review of the Dinematichthyini of the Indowest Pacific. The genera reviewed here are not necessarily closely related to each other, but are compiled in this volume because they are obviously not related to the three other groups reviewed or under review - Diancistrus and two related genera (see part I, Schwarzhans et al., 2005), the Dermatopsis - Dipulus group (see part II, M ller and Schwarzhans, 2006) and Dinematichthys sensu latu (in preparation). These 11 genera are mainly distinguished by pseudoclasper morphology, meristics, otolith morphology and presence or absence of the upper preopercular pore. The main distinguishing characters of the species contained in these genera are vertebrae and fin ray counts, morphometric characters, head squamation and the morphology of otoliths and pseudoclaspers.

Stock structure of Japanese flounder inferred from morphological and genetic analyses

Stock structure of Japanese flounder Paralichthys olivaceus has been inferred mainly from either morphological or genetic analyses. However, because the results of both analyses did not always agree with each other, an inclusive conclusion has never been obtained. In this study, the stock structure has been inferred from both morphological and genetic analyses using 722 wild Japanese flounder collected from nine locations along the Japanese coast. The dorsal and anal fin ray counts were larger in the southern than in the northern populations. In total, 1041 bp of mitochondrial NADH dehydrogenase subunit-2 (ND2) and 1830 bp of ND5 sequences were aligned. There are 578 variable sites in the concatenated sequence from the two genes, which defined a total of 490 haplotypes. Both results of morphological and genetic analyses indicated that the western Kyushu group, which included the Nagasaki and Kagoshima populations, was divided from the other seven populations. This is the first report to reveal the heterogeneity of the western Kyushu group based on statistical analysis.