Morphometric and meristic variation in Galician threespine stickleback populations,northwest Spain

Synopsis We evaluated morphological differentiation among populations of threespine stickleback, Gasterosteus aculeatus, from the Limia and Miño basins (Galicia, NW Spain), the river Karup (Denmark) and Aiguamolls de l’Empordà (Girona, northeast Spain), using multivariate analysis of morphometric and meristic characters. Multivariate discriminant analysis and hierarchical cluster analysis uncovered significant differences among the four main groups, between the two groups from Galicia and among populations within the Miño basin. The stickleback from Galicia differed from the Danish group in head and body armour characters. Between the Miño and Limia groups, we found differences in both head and body proportions as well as in number of gill rakers. Within the Miño basin populations varied with respect to head and body armour traits and the number of lower gill rakers. Clustering analysis divided these populations into two groups based on the latter trait: fish from the upper section of river Miño and tributaries (a lower number of lower gill rakers) and fish from the central and lower reaches of the river. Overall, morphometric traits were more useful than meristic ones; however, the two types of data provided congruent information about the morphological differentiation of stickleback populations.     

Discrimination of Baltic herring populations with respect to Anisakis simplex larvae infection

Samples of herring Clupea harengus in the Baltic were collected during the spawning season in western, middle and eastern waters off the Polish coast. Two samples were taken per area, several morphometric characters were measured and some meristic characters (vertebrae and gill rakers) were counted. Infection with Anisakis simplex larvae, total length, age and maturity stage were recorded. Univariate and multivariate statistical tests were used to compare the samples, discriminant analysis was applied to separate herring populations and the fraction of herring populations in each area was estimated. The results obtained indicated that infected fish represented a mixed group of western and central Baltic herring. In the first samples collected from each area, the share of the western population decreased from 40% in the western to 18% in the middle and 13% in the eastern coasts. The share of western herring was higher in the second samples collected in the same area and decreased from 91% in the western coast to 14 and 32% in the middle and eastern ones, respectively.     

A new anchovy, <Emphasis Type="Italic">Stolephorus teguhi</Emphasis> (Clupeiformes: Engraulidae), from North Sulawesi,Indonesia

Stolephorus teguhi sp. nov. is described from the holotype and 14 paratypes, 49–77 mm in standard length, collected from North Sulawesi, Indonesia. The species is characterized by having numerous gill rakers (31–35 + 41–46 = 72–82) and a short upper jaw, its posterior tip reaching to or extending slightly beyond the anterior margin of the preopercle. Stolephorus pacificus and S. multibranchus also have relatively numerous gill rakers for species of this genus (21–27 + 29–36 = 53–61 and 21–28 + 30–35 = 54–60, respectively), but counts for S. teguhi exceed those for the two species. Although S. advenus also has a short upper jaw similar to that of S. teguhi, the former has far fewer gill rakers (19 + 24 = 43) than the latter.     

Osteology and morphology of the characiform fish Alestes stuhlmanniiPfeffer, 1896(Alestidae) from the Rufiji River basin,East Africa

The osteology of a population of the characiform fish Alestes stuhlmannii, from the Rufiji River basin of Tanzania, is described, and meristic and morphometric data from over 100 specimens, ranging from 15·5 to 218 mm standard length are given. Two allometric changes occur during growth of this fish: both the number of gill rakers and the interorbital width relative to the head length increase with size. There are also changes in tooth form associated with growth in A. stuhlmannii, with the unicuspid teeth of juveniles becoming almost molariform in adults. This change in dentition with age, and therefore size, may have implications for recognizing taxa, some of which (the fossil genera Sindacharax and Bunocharax, and the living dwarf petersiines) have been distinguished by jaw or dental characters.     

Meristic and morphometric variations in fluvial Japanese charr between river systems and among tributaries of a river system

Meristic and morphometric characters of local populations of fluvial Japanese charr, Salvelinus leucomaenis, which have been isolated above dams and a waterfall, were compared between river systems (Naka and Tone rivers, central Japan) and among the tributaries of the Naka River (Ashinagasawa, Akasawa, Ushirosawa and Moto-okashirasawa streams). Between the river systems, there was a significant difference in the mean number of dorsal fin rays, pyloric caeca, white spots under the lateral line and the proportion of the diameter of the white spots to the diameter of the pupil, respectively. On the other hand, among the tributaries within a river system, a significant difference was occurred in the mean number of anal fin rays, pored scales on the lateral line, gill rakers, vertebrae, pyloric caeca, white spots under the lateral line, white spots on the surface of the gill covers and the proportion of the diameter of the white spots to the diameter of the pupil, respectively. A dendrogram based on data of the meristic and morphometric characters showed that the population of the Tone River was included within the variation detected among the tributary populations of the Naka River. Meristic and morphometric characters of Japanese charr varied not only between river systems but also among tributaries within a river system.     

Variation in number of vertebrae and gill rakers of sockeye salmon,Oncorhynchus nerka,in North America

Synopsis The latitudinal, regional, and annual variation in number of vertebrae and number of gill rakers present in sockeye salmon, Oncorhynchus nerka, stocks in North America was examined. Stocks in more northern areas had higher numbers of vertebrae and gill rakers than did those in more southern ones. Significant annual variability in the frequencies of these meristic characters within stocks was observed. When stocks were grouped into three regions (southern, central, and northern), heterogeneity in vertebral and gill raker frequencies was greater among regions than among stocks within the regions. Similarly, heterogeneity was greater among stocks than among sampling years within stocks. Differences in vertebral and gill raker frequencies are only useful for stock identification of sockeye salmon on a broad regional basis.     

Deepsea herrings (Bathyclupeidae) of the northwestern Pacific ocean

Deepsea herrings of the northwestern Pacific (waters of Japan and Taiwan) are revised. Three species are recognized in this area, and two of them described as new: B. gracilis Fowler, 1938, B. japanotaiwana sp. n., and B. nikparini sp. n. B. japanotaiwana was previously mistakenly identified as the western Atlantic species B. argentea; actually it is especially similar to B. malayana, from which it differs in the bicolor oral cavity and in some meristic characters. B. nikparini is especially close to the Caribbean species B. schroederi, from which it differs in a greater number of developed gill rakers and smaller number of rays in the anal fin.     

Population structure and biology of alewives (Alosa pseudoharengus) and blueback herring (A. aestivalis) in the Saint John River,New Brunswick

Synopsis Examination of more than 2,000 alewives (Alosa pseudoharengus) and blueback herring (A. aestivalis) from various areas in the Saint John River, N.B., showed differences in their morphometric and meristic characters. They differed also in length and age, compositions, spawning time, length and age at maturity, back-calculated lengths, and growth parameters. Within each species, between-area comparisons showed significant differences in some of their meristic characteristics.To test a homing hypothesis for alewives, a multivariate analysis was performed on eight meristic characters. Two discriminant function programs, discriminant analysis for two groups and a multiple group stepwise discriminant analyses were used. Values of the generalized Mahalanobis D² and percent overlap in frequency distributions of meristic characters suggest that considerable straying of fish, especially between adjacent areas occurs during upstream spawning migration.This article is one of several papers presented at the Second European Ichthyological Congress, Paris, 8–15 September 1976, to be published in Environmental Biology of Fishes.     

<Emphasis Type="Italic">Paraliparis adustus</Emphasis> and <Emphasis Type="Italic">Paraliparis bullacephalus</Emphasis>: two new snailfish species (Teleostei: Liparidae) from Alaska

Paraliparis adustus sp. nov., a snailfish species from the Bering Sea near the Aleutian Island Archipelago, Alaska, is described based on a single mesopelagic specimen. This new species is clearly distinguished by a combination of several morphological features and meristic counts, including long pointed gill rakers with 0–3 spinules at or near the tip, anus positioned forward near the pectoral symphysis, and color uniform brown. Paraliparis bullacephalus sp. nov. from Shelikof Strait, Gulf of Alaska, is also described. This new species is very similar in meristic characters and general body shape and size to P. holomelas Gilbert, but differs primarily in morphological features of the head, particularly in the shape of the dorsal contour of the head, snout, and opercular flap, mouth size, and eye position.     

Quantitative Trait Loci Analyses for Meristic Traits in Oncorhynchus mykiss

Meristic trait variation among species and populations has long been used as the basis for identification and classification of fishes. Within Oncorhynchus mykiss, there is considerable variation in meristic characters such as numbers of vertebrae, lateral line scales, fin rays, gill rakers, and pyloric caeca. In our laboratory the Oregon State University (OSU) rainbow trout and the Clearwater River (CW) steelhead trout clonal lines, produced by androgenesis, exhibit significant differences in values for meristic traits, making quantitative trait locus (QTL) analysis of these meristic characters possible. Our objective was to determine the number, location, and effects of QTL associated with meristic characters in order to test two hypotheses: (1) that QTL for different meristic traits co-localize to the same linkage group and (2) that meristic trait QTL co-localize to the same linkage group as a previously identified development rate QTL. Doubled haploid individuals, produced by androgenesis from sperm from an F₁ hybrid between the OSU and CW lines, were used to evaluate the joint segregation of each meristic phenotype and Amplified Fragment Length Polymorphic marker genotypes. Composite interval mapping revealed QTL for six of the seven traits analyzed. One QTL each for scales above the lateral line and for gill rakers co-localized to the same position. Only one QTL for scales above the lateral line co-localized to the same region as that for the development rate QTL, but a greater map resolution is necessary to determine if these loci are truly the same. We failed to detect pleiotropy for most meristic trait QTL. Our results suggest that different major loci are associated with variation in each meristic character and that the expression of these loci may be influenced by maternal and external environmental factors.     

Allometric variation and sexual dimorphism in <Emphasis Type="Italic">Lycodes yamatoi</Emphasis> Toyoshima, 1985 (Perciformes: Zoarcidae) from the Sea of Japan

A detailed analysis of allometric variation and sexual dimorphism in Lycodes yamatoi (Perciformes: Zoarcidae) was carried out using an original method developed by the authors. An allometric pattern of growth was revealed not only in plastic but in some meristic characters, such as the number of teeth on the bones of the mouthparts and the number of gill rakers on the first gill arc. It was determined that most of the morphological characters of L. yamatoi were subjected to positive allometric variability (the proportions of the head and the anterior part of the body), while growth of the remaining characters was specified by negative allometry (the length of the rays of pair and caudal fins, interorbital distance, and isthmus width) and isometry (the standard length, ante-anal distance, and head width on the vertical neck). The juveniles of L. yamatoi have no significant sexual distinctions either in plastic or in meristic characters. Adult females and males of L. yamatoi significantly differed by characters composing the head complex, the actual length of the head, and correlatively related with it ante-dorsal and ante-pectoral distances. The dimensional indexes of antedorsal and ante-pectoral distances, and the relative sizes of maxillary bones (lmx/c) are of the greatest diagnostic value for sex differentiation.     

<Emphasis Type="Italic">Johnius</Emphasis> (<Emphasis Type="Italic">Johnius</Emphasis>) <Emphasis Type="Italic">majan</Emphasis> sp. nov., a sciaenid fish (Pisces: Sciaenidae) from Oman,Indian Ocean

Johnius (Johnius) majan sp. nov. is described on the basis of 8 specimens (117–158 mm in standard length) from Oman, Indian Ocean. The new species is distinguished from its congeners by the following combination of characters: black axillary spot on upper pectoral fin base; dorsal soft rays 29–32; anal soft rays 8; scales above lateral line 6, below 11; eye diameter 22.9–28.9% HL; interorbital width 32.0–38.0% HL; gill rakers 5–6 + 15–18 = 21–24; no mental barbel; last well developed pleural rib on 7th vertebra; swim bladder appendages 11; vertebrae 10 + 14 = 24.     

Production and characterization of intergeneric somatic hybrids between <Emphasis Type="Italic">Brassica napus</Emphasis> and <Emphasis Type="Italic">Orychophragmus violaceus</Emphasis> and their backcrossing progenies

Alien chromosome addition lines have been widely used for identifying gene linkage groups, assigning species-specific characters to a particular chromosome and comparing gene synteny between related species. In plant breeding, their utilization lies in introgressing characters of agronomic value. The present investigation reports the production of intergeneric somatic hybrids Brassica napus (2n = 38) + Orychophragmus violaceus (2n = 24) through asymmetric fusions of mesophyll protoplasts and subsequent development of B. napus-O. violaceous chromosome addition lines. Somatic hybrids showed variations in morphology and fertility and were mixoploids (2n = 51–67) with a range of 19–28 O. violaceus chromosomes identified by genomic in situ hybridization (GISH). After pollinated with B. napus parent and following embryo rescue, 20 BC₁ plants were obtained from one hybrid. These exhibited typical serrated leaves of O. violaceus or B. napus-type leaves. All BC₁ plants were partially male fertile but female sterile because of abnormal ovules. These were mixoploids (2n = 41–54) with 9–16 chromosomes from O. violaceus. BC₂ plants showed segregations for female fertility, leaf shape and still some chromosome variation (2n = 39–43) with 2–5 O. violaceus chromosomes, but mainly containing the whole complement from B. napus. Among the selfed progenies of BC₂ plants, monosomic addition lines (2n = 39, AACC + 1O) with or without the serrated leaves of O. violaceus or female sterility were established. The complete set of additions is expected from this investigation. In addition, O. violaceus plants at diploid and tetraploid levels with some variations in morphology and chromosome numbers were regenerated from the pretreated protoplasts by iodoacetate and UV-irradiation. Z. Zhao and T. Hu make equal contributions to this work.     

Morphology and mitochondrial DNA variation of the Siberian whitefish <Emphasis Type="Italic">Coregonus lavaretus pidschian</Emphasis> (Gmelin) in the upstream water bodies of the Ob and Yenisei Rivers

Combining morphological, ecological and genetic analyses, we compared patterns of diversification within and among populations of the southern Siberian whitefish species Coregonus lavaretus pidschian (Gmelin) to illuminate their evolutionary history. Using sequencing data from 1,930 bp of NADH dehydrogenase subunit 1 (ND1) mitochondrial DNA regions, we documented phylogeographic relationships among populations and developed a phylogeny of mtDNA haplotypes. We found significant differences in the perforated lateral-line scale numbers within and between some populations. Clear differences in the number of gill rakers on the first branchial arch were only exhibited between populations of C. l. pidschian and Coregonus lavaretus pravdinellus Dulkeit. Concordance between different morphological groups based on two meristic traits and mtDNA patterns was also tested.     

Deep genetic differentiation between two morphologically similar species of wolf herrings (Teleostei,Clupeoidei, Chirocentridae)

Wolf herrings (Chirocentridae; Clupeoidei) are commonly found in local fish markets throughout the Indo‐West Pacific region where they constitute an auxiliary source of food and income for local communities. The validity of the two species of wolf herrings, Chirocentrus dorab Forsskål, 1775 and C. nudus Swainon, 1839, is only supported by slight morphological differences. The identification of either species is challenging, especially for juveniles, and precludes accurate assessments of these natural resources at a species level. As a step towards gaining better knowledge of the genetic structure of these fishes, we examined genetic differentiation between these two species by reconstructing their entire mitogenomic sequences using high‐throughput sequencing technology. We found that the mitogenome of each species shared the same gene content and order that were the same for those found in most other teleost fishes. Despite their high morphological similarity, these two species of Chirocentrus were genetically well differentiated (p‐distance = 16.3% at their cytochrome oxidase I). A mitogenomic time‐calibrated phylogenetic analysis showed that wolf herrings originated about 35 million years ago, and they represent a case of morphological stasis. Furthermore, comparison of published and newly determined mitochondrial COI barcode region sequences from 22 individuals revealed species‐level cryptic genetic diversity within C. dorab. Altogether, these mitochondrial data are effective in discriminating species within this genus and informing population genetic relationships within species of wolf herrings.     

Length–weight relationships for eight fish species from the Ravi River,north‐western India

Length–weight relationships (LWRs) were evaluated for Badis badis (n = 25), Sperata seenghala (n = 26), Labeo gonius (n = 34), Rasbora rasbora (n = 30), Bagarius bagarius (n = 24), Gagata cenia (n = 27), Glyptothorax stoliczkae (n = 24) and Channa orientalis (n = 28) from the Ravi River tributary in North India. Altogether 218 samples of eight species were obtained between May and November 2014 using cast nets and gill nets. LWRs for these species were unknown to FishBase, and new maximum lengths were recorded for two of these species.     

Morphometric variation of snakehead fish,Channa punctatus,populations from three Indian rivers

The present study was undertaken with the objective to investigate the intraspecific variation of Channa punctatus on the basis of morphometric characters using the truss network system that was constructed from the fish body. Fish samples were collected from the Narora (n = 62) and Kanpur sites (n = 46) of the Ganga River, the Firozabad site in the Yamuna River (n = 66) and at the Lucknow site of the Gomti River (n = 60). Data were subjected to principal component analysis, discriminant function analysis and univariate analysis of variance. The first principal component (PC I) analysis explained 47.75% of total variation while PC II and PC III explained 8.18 and 7.48%, respectively. The step‐wise discriminant function analysis retained seven variables that significantly discriminated the populations. Using these variables 81.85% of the original groups were classified into their correct samples. Misclassification was higher for the samples from Ganga River (19.6% at the Kanpur site and 19.4% for the Narora site). Of the total 27 transformed morphometric measurements, 23 exhibited significant differences among the populations. These findings indicate the presence of different stocks of fish from the three rivers.     

Response of splenic melanomacrophage centers of Oreochromis niloticus (Linnaeus, 1758) to inflammatory stimuli by BCG and foreign bodies

The study objective was to make histological, histochemical and morphometric evaluations on the splenic Melanomacrophage centers (MMCs) of tilapias, Oreochromis niloticus (Linnaeus, 1758), that were subjected to chronic inflammation stimuli by implantation (IMP) of a glass coverslip in the subcutaneous tissue and through inoculation of the bacillus Calmette‐Guerin (BCG). Randomly distributed in four groups were 150 tilapias: IMP (n = 45); IMP+BCG (n = 45); BCG (n = 45); and control (n = 15). Nine fish per treatment and three control fish were sampled on days 3, 7, 14, 21 and 33. The results demonstrated that increased numbers and areas of these structures were related to the type of stimulus, and that these were greater for the specific response. The principal pigment component identified was hemosiderin. Results suggest that the intensity of the MMC response in O. niloticus depended on the type of inflammatory stimulus used, and that it was greater in fish inoculated with BCG, which induced a granulomatous inflammation when compared to the foreign body inflammatory response induced by the glass coverslips.     

Morphological variations among four riverine populations (Bangladesh) of endangered catfish Rita rita (Hamilton, 1822)

The morphological variation of the endangered catfish Rita rita was studied based on meristic, length–weight relationship (LWR), traditional (TRA) and truss (TRU) distance based morphometric analysis of 200 juveniles collected from the Old Brahmaputra, Jamuna, Meghna and Kangsa rivers. Data were subjected to Kruskal–Wallis test for meristic counts, t test for LWR, univariate ANOVA, multivariate discriminant function analysis and canonical analysis (CA) both for TRA and TRU morphometric characters to discriminate the populations. Kruskal–Wallis test denoted that only one (caudal fin rays) out of six meristic counts was significantly (p < .05) variable among the stocks. One sample t test clarified that all parameters of LWR were significantly (p < .05) differentiated in all stocks. Univariate ANOVA revealed significant (p < .001, p < .01, and p < .05) differences among the four stocks in 14 of 15 standardized TRA traits and 17 of 25 TRU distances, respectively. The first discriminant function (DF1) explained 59.4% and 68.0% of total variance, while 30.6% and 23.1% by DF2, 10.0% and 8.9% by DF3 for TRA and TRU features, respectively among the stocks. CA showed a clear separation of the stocks both for TRA and TRU measurements. The overall random assignment of individuals into their original groups was high as 78.5% for TRA and 78.0% for TRU characters, respectively, indicating that all the four stocks are highly divergent from each other. The results exposed existence of four distinct phenotypic stocks of R. rita in the tested rivers.