Comparative analysis of intermuscular bones in three strains of common carp

The objective was to document the variations in the intermuscular bone counts among three carp strains: mirror carp, hybrid carp [Boshi carp (Cyprinus pellegrini) × Heilongjiang carp (Cyprinus carpio)], and a cold‐resistant strain of Hebao carp. The intermuscular bone counts, lengths, and weights were obtained from 146 fish; the bone count ranged from 55 to 110 (mean 92.85) among the three strains. Mirror carp had the lowest number of intermuscular bones and a higher coefficient of variation in counts relative to the other two species. There was no relationship between the intermuscular bone counts to standard length or body length. Similarly, there was no difference in the intermuscular bone count or shape between the left and right sides of the body. However, the count was significantly higher (P < 0.01) in the anterior region (snout to cloaca: 54% of the total count) than in the posterior region (cloaca to base of caudal fin: 46% of the total count). There was a significant difference between strains (P < 0.0001), but not between age classes; a significant difference was also observed in the posterior region counts among strains, but not in the anterior region (P < 0.0001). Similarly, the difference in counts in the posterior region was primarily related to differences in the counts of three of the six types: non‐forked (I), tree‐branch and two‐end‐bi‐fork type. Our results suggest that selective breeding protocols should target a reduction in the number of intermuscular bones in the posterior region, particularly in mirror carp.     

Induction of Gynogenesis in Japanese Crucian Carp (Carassius cuvieri)

Diploid gynogenesis was induced in Japanese crucian carp (Carassius cuvieri) eggs using UV-irradiated genetically inactive spermatozoa from mirror carp (Cyprinus carpio L.) or blunt snout bream (Megalobrama amblycephala), with or without cold shock. The optimal radiation dosage was 4200 mJ/cm² and 3600 mJ/cm² for mirror carp and blunt snout bream sperm, respectively. At this dosage and without cold shock, the yields were (32.4±3.3)% vs. (33.8±1.4)% gynogenetic haploids and (0.7±0.3)% vs. (0.5±0.3)% hybrid diploids, respectively. At the optimal UV dosage but with cold shock (2 min after fertilization, 0-4°C for 40 min), the hatching rates were (27.8±2.1)% and (29.4±3.3)%, respectively. From hatching to feeding, (15.7±3.4)% and (23.6±4.1)% normal gynogenetic diploids were recorded, respectively. Survival of normal gynogenetic diploids was 56% out of the hatched fry when using irradiated spermatozoa of mirror carp, which was lower than that (up to 80%) when using irradiated spermatozoa of blunt snout bream. This indicated that the sperm of blunt snout bream, with distant genetic relation to the maternal Japanese crucian carp, was more effective than that of mirror carp to induce diploid gynogenesis. The nature of the gynogenetic progeny was identified with external appearance, chromosome number and gonad structure. The presence of only females in gynogenetic progeny probably suggested XX genotype in the female Japanese crucian carp. The gynogenetic diploids have potential values such as faster growth and stronger disease resistance than the normal Japanese crucian carp. All gynogenetic progeny possessed 100 chromosomes whereas all J x B crosses were triploid with 124 chromosomes. The formation of the new triploid hybrids in J x B crosses may be useful in aquaculture.     

Fin tissues as surrogates of white muscle when assessing carbon and nitrogen stable isotope levels for Arctic and brook char

Arctic char (Salvelinus alpinus) are a fish species ubiquitous to the fresh waters of Arctic region and brook char (Salvelinus fontinalis) are similarly common across the sub-Arctic region of eastern Canada. Populations can be small in numbers, especially farther north thus it is important to develop non-lethal methods of sampling these fish to minimize the invasiveness and impact of scientific research. We examined the stable isotopes of nitrogen and carbon in white muscle, caudal fin, and adipose fin tissues of Arctic char and brook char (S. fontinalis) from northern Quebec and Labrador, Canada. Our results revealed several broad conclusions. First, differences among muscle, caudal fin, and adipose fin tissues were ~1?‰ for freshwater Arctic and brook char. Second, the two species within the same drainage had similar stable isotope levels and tissue differences. Third, anadromous Arctic char show similar, non-significant differences among these tissues for δ¹⁵N, but muscle δ¹³C was highly enriched. Fourth, the stable isotope levels and tissue differences were the same for anadromous Arctic char from two watersheds where char use distinctly different ocean environments. Overall, it appears that caudal fin tissue in particular is a useful surrogate for white muscle δ¹³C and δ¹⁵N levels for Arctic and brook char in this region and thus, a non-lethal collection of a small sample of caudal fin tissue will provide an accurate measure of white muscle isotope levels.     

Concentrations of a Koi herpesvirus (KHV) in tissues of experimentally infected Cyprinus carpio koi as assessed by real-time TaqMan PCR

The Koi herpesvirus (KHV) is a herpes-like virus now recognized as a worldwide cause of mortality among populations of koi Cyprinus carpio koi and common carp Cyprinus carpio carpio. Temperature is a key factor influencing virus replication both in cell culture and in the tissues of experimentally infected fish. Genomic DNA sequences were used to optimize a rapid real-time TaqMan PCR assay to detect and quantify KHV DNA as found in the tissues of virus-exposed fish. The assay allowed analytical enumeration of target KHV genome copies ranging from 10(1) to 10(7) molecules as present in infected cell lines or fish tissues. The new assay was specific for KHV and did not detect DNA from 3 related herpes-like viruses found in fish, the Cyprinid herpesvirus 1 (CyHV-1), Cyprinid herpesvirus 2 (CyHV-2), Ictalurid herpesvirus 1 (IcHV-1) or the KF-1 cell line used for virus growth. Concentrations of KHV DNA were evaluated in 7 different tissues of replicate groups of virus-exposed koi held at water temperatures of 13, 18, 23 and 28 degrees C. Viral DNA was detected among virus-exposed koi at all 4 water temperatures but mortality was only observed among fish at 18, 23, and 28 degrees C. Time and temperature and the interactions between them affected concentrations of viral DNA detected in tissues of koi exposed to KHV. Although there were no recognized patterns to viral DNA concentrations as found in different tissues over time, KHV genome copies for all tissues increased with time post virus exposure and with water temperature. The remarkably rapid and systemic spread of the virus was demonstrated by the presence of viral DNA in multiple tissues 1 d post virus exposure. The greatest DNA concentrations found were in the gill, kidney and spleen, with virus genome equivalents consistently from 10(8) to 10(9) per 10(6) host cells. High levels of KHV DNA were also found in the mucus, liver, gut, and brain. Koi surviving infection at 62 to 64 d post virus exposure contained lower KHV genome copies (up to 1.99 x 10(2) per 10(6) host cells) as present in gill, kidney or brain tissues.     

鲑鱼胰岛素样生长因子I cDNA在镜鲤中的表达

通过显微注射技术,将冠以鲤鱼β－肌动蛋白基因（ＣＡ）启动调控顺序的鲑鱼胰岛素样生长因子Ｉ（ｓＩＧＦ－Ｉ）的ｃＤＮＡ,即ＣＡｓＩＧＦｃ注入镜鲤受精卵内,经聚合酶链式反应（ＰＣＲ）技术检测,受本胚胎发育各期均携有外源基因拷贝。     

Neolumpenus unocellatus,a new genus and species of stichaeid fish from Japan

Neolumpenus unocellatus gen. et sp. nov., a stichaeid fish (subfamily Lumpeninae,sensu Makushok, 1958) is described on the basis of a single specimen found in the stomach of the Pacific cod,Gadus macrocephalus Tilesius, caught off Akkeshi, Hokkaido, Japan. The new genus and species is distinguished from all other lumpenines in having the following combination of characters: 1) 51 dorsal spines, 33 anal fin rays, 57 total vertebrae; 2) broad pelvic fin with deeply-branched soft rays; 3) lower rays of pectoral fin branched and not prolonged backward; 4) prevomerine and palatine teeth present; 5) pungent spines present in pelvic and anal fins; 6) upper lip fused to snout anteriorly; 7) gill openings not extending forward beyond a vertical through posterior margin of eye; 8) minimal (fifth) hypural present; 9) first interneural spine inserted between first and second neural spines; 10) extremely large cephalic sensory pores present; 11) high, steep snout; 12) ocellus on dorsal base of caudal fin.     

Limited dedifferentiation provides replacement tissue during zebrafish fin regeneration

Unlike humans, some vertebrate animals are able to completely regenerate damaged appendages and other organs. For example, adult zebrafish will regenerate the complex structure of an amputated caudal fin to a degree that the original and replacement fins are indistinguishable. The blastema, a mass of cells that uniquely forms following appendage amputation in regenerating animals, is the major source of regenerated tissue. However, the cell lineage(s) that contribute to the blastema and their ultimate contribution(s) to the regenerated fin have not been definitively characterized. It has been suggested that cells near the amputation site dedifferentiate forming multipotent progenitors that populate the blastema and then give rise to multiple cell types of the regenerated fin. Other studies propose that blastema cells are non-uniform populations that remain restricted in their potential to contribute to different cell lineages. We tested these models by using inducible Cre-lox technology to generate adult zebrafish with distinct, isolated groups of genetically labeled cells within the caudal fin. We then tracked populations of several cell types over the entire course of fin regeneration in individual animals. We found no evidence for the existence of multipotent progenitors. Instead, multiple cell types, including epidermal cells, intra-ray fibroblasts, and osteoblasts, contribute to the newly regenerated tissue while remaining highly restricted with respect to their developmental identity. Our studies further demonstrate that the regenerating fin consists of many repeating blastema "units" dedicated to each fin ray. These blastemas each have an organized structure of lineage restricted, dedifferentiated cells that cooperate to regenerate the caudal fin.     

Two different transgenes to study gene silencing and re-expression during zebrafish caudal fin and retinal regeneration

We used the 500-bp Xenopus ef1-alpha promoter and the 2-kb zebrafish histone 2A.F/Z promoter to generate several independent transgenic zebrafish lines expressing EGFP. While both promoters drive ubiquitous EGFP expression in early zebrafish development, they are systematically silenced in several adult tissues, including the retina and caudal fin. However, EGFP expression is temporarily renewed in the adult during either caudal fin or retinal regeneration. In the Tg(H2A.F/Z:EGFP)nt line, EGFP is moderately expressed in both the wound epithelium and blastema of the regenerating caudal fin. In the Tg(ef1-alpha:EGFP)nt line, EGFP expression is reinitiated and restricted to the blastema of the regenerating caudal fin and colabels with BrdU, PCNA, and msxc-positive cells. Thus, these two ubiquitous promoters drive EGFP transgene expression in different cell populations during caudal fin regeneration. We further analyzed the ability of the ef1-alpha:EGFP transgene to label nonterminally differentiated cells during adult tissue regeneration. First, we demonstrated that the transgene is highly methylated in adult zebrafish caudal fin tissue, but not during fin regeneration, implicating methylation as a potential means of transgene silencing in this line. Next, we determined that the ef1-alpha:EGFP transgene is also re-expressed during adult retinal regeneration. Specifically, the ef1-alpha:EGFP transgene colabels with PCNA in the Müller glia, a specialized cell that is the source of neuronal progenitors during zebrafish retinal regeneration. Thus, we concluded that Tg(ef1-alpha:EGFP)nt line visually marks nonterminally differentiated cells in multiple adult regeneration environments and may prove to be a useful marker in tissue regeneration studies in zebrafish.     

Histopathological and ultrastructural features of Koi herpesvirus (KHV)-infected carp Cyprinus carpio, and the morphology and morphogenesis of KHV

Epizootics of Koi herpesvirus (KHV) cause mass mortalities in koi carp and common carp worldwide. We used a newly developed 'per-gill infection' procedure with live KHV, and then conducted detailed histopathological and ultrastructural studies of KHV-infected cells including an examination of the morphology and morphogenesis of KHV. The primary target of KHV was respiratory epithelial cells of the gill lamellae, and release of virions from infected epithelial cells resulted in a systemic infection affecting the kidney, spleen, heart, brain and liver. The pathognomonic feature of infected cells was the formation of intranuclear inclusion bodies with marginal hyperchromatosis in the nucleus. Within the nucleus, assembly of capsids and nucleocapsids and an increase in filamentous nucleoproteins were evident. Enveloped nucleocapsids budded from the inner nuclear membrane into the perinuclear space. De-enveloped nucleocapsids were translocated in the cytoplasm to be embedded within inclusion bodies where tegumentation of the nucleocapsid occurred. Enveloped virions that had budded into intracytoplasmic vesicles and virions located extracellularly were composed of an electron-dense core, surrounded in turn by the capsid, the tegument and finally an envelope with projections. The morphology and morphogenesis of KHV were the same as those of viruses within the family Herpesviridae.     

Koi herpesvirus infection in experimentally infected common carp Cyprinus carpio (Linnaeus, 1758) and three potential carrier fish species Carassius carassius (Linnaeus, 1758); Rutilus rutilus (Linnaeus, 1758); and Tinca tinca (Linnaeus, 1758) by quantitative real‐time PCR and in‐situ hybridization

Only single cells in the carrier fish species Carassius carassius (Linnaeus, 1758) for koi herpesvirus (KHV) are infected in contrast to large numbers in the susceptible species common carp Cyprinus carpio (Linnaeus 1758). Several species of the family Cyprinidae have been described as virus carrier species, showing no clinical signs of a KHV disease but able to transmit the virus to other susceptible fish. In this study, 72 common carp Cyprinus carpio (Linnaeus, 1758), 36 tench Tinca tinca (Linnaeus, 1758), 36 crucian carp Carassius carassius (Linnaeus, 1758) and 36 common roach Rutilus rutilus (Linnaeus, 1758) were experimentally infected with KHV (isolate “Israel”) by immersion and kept at 20°C. The fish were euthanized at 12 timepoints over a period of 90 days and virus DNA was quantified in tissues by a real‐time TaqMan PCR. Whereas KHV‐DNA was found in Cyprinus carpio for up to 90 days, the virus DNA was detectable only in single individuals of Rutilus rutilus, Tinca tinca and Carassius carassius for up to 25 days after experimental virus exposure. Tissue samples of Cyprinus carpio and Carassius carassius were screened by in‐situ hybridization. Positive signals were found in various organs of the common carp tested crucian carp. In the latter species a much smaller number of virus‐positive stained cells was detected compared to the infected carp.     

Cloning of the koi herpesvirus genome as an infectious bacterial artificial chromosome demonstrates that disruption of the thymidine kinase locus induces partial attenuation in Cyprinus carpio koi

Koi herpesvirus (KHV) is the causative agent of a lethal disease in koi and common carp. In the present study, we describe the cloning of the KHV genome as a stable and infectious bacterial artificial chromosome (BAC) clone that can be used to produce KHV recombinant strains. This goal was achieved by the insertion of a loxP-flanked BAC cassette into the thymidine kinase (TK) locus. This insertion led to a BAC plasmid that was stably maintained in bacteria and was able to regenerate virions when permissive cells were transfected with the plasmid. Reconstituted virions free of the BAC cassette but carrying a disrupted TK locus (the FL BAC-excised strain) were produced by the transfection of Cre recombinase-expressing cells with the BAC. Similarly, virions with a wild-type revertant TK sequence (the FL BAC revertant strain) were produced by the cotransfection of cells with the BAC and a DNA fragment encoding the wild-type TK sequence. Reconstituted recombinant viruses were compared to the wild-type parental virus in vitro and in vivo. The FL BAC revertant strain and the FL BAC-excised strain replicated comparably to the parental FL strain. The FL BAC revertant strain induced KHV infection in koi carp that was indistinguishable from that induced by the parental strain, while the FL BAC-excised strain exhibited a partially attenuated phenotype. Finally, the usefulness of the KHV BAC for recombination studies was demonstrated by the production of an ORF16-deleted strain by using prokaryotic recombination technology. The availability of the KHV BAC is an important advance that will allow the study of viral genes involved in KHV pathogenesis, as well as the production of attenuated recombinant candidate vaccines.     

人工诱导雌核发育日本白鲫

分别用遗传失活的散鳞镜鲤(Cyprinus carpio L.)、团头鲂(Megalobrama amblycephala)精子诱导日本白鲫(Carassius cuvieri)进行雌核发育.未经冷休克处理,用UV照射过的镜鲤的精子(其最佳UV照射剂量为4 200 mJ/cm2)与日本白鲫卵子受精获得(32.4±3.3)%雌核发育单倍体和(0.7±0.3)%杂交二倍体,而照射过的团头鲂精子(其最佳UV照射剂量为3 600mJ/cm2)与日本白鲫卵子受精得到了(33.8±1.4)%雌核发育单倍体和(0.5-±0.3)%杂交二倍体.日本白鲫卵子分别经灭活的镜鲤、团头鲂的精子激活(精子经各自最佳UV剂量处理),施以冷休克处理(受精后2min,0-4℃,40min),其孵化率分别为(27.8±2.1)%和(29.4±3.3)%,发育到摄食期,其正常的雌核发育二倍体鱼苗分别为(15.7±3.4)%和(23.6±4.1)%,在镜鲤实验组中,其正常的雌核发育二倍体鱼苗占孵化鱼苗总数的56%,这比团头鲂实验组中正常雌核发育二倍体鱼苗的比率(达到80%)低,结果表明诱导日本白鲫雌核发育,与母本遗传关系远的团头鲂精子较镜鲤的更有效.从染色体数目、外形特征和性腺结构等方面证实雌核发育后代的生物学特性.雌核发育日本白鲫全为雌性,这表明其雌性是同配XX型.雌核发育日本白鲫在生产上将有着潜在的价值,如比普通日本白鲫长得更快,抗病能力强等.所有的雌核发育日本白鲫的染色体数目都是100,而所有的团头鲂与日本白鲫的杂交后代都是三倍体(3n=124),新三倍体鱼在鱼类养殖和理论研究中将存在潜在的价值.     

Conditions for initiating Lake Victoria haplochromine (Oreochromis esculentus) primary cell cultures from caudal fin biopsies

The global decline of freshwater fishes has created a need to cryopreserve biological materials from endangered species in an effort to conserve the biodiversity within this taxon. Since maternal gametes and embryos from fish are difficult to cryopreserve, somatic cells obtained from caudal fins have become an increasingly popular resource as they contain both maternal and paternal DNA ensuring valuable traits are not lost from the population. Somatic cells stored in cryobanks can be used to supplement endangered populations with genetically valuable offspring with the use of assisted reproductive technologies. However, initiating primary cell cultures from caudal fin biopsies of endangered species can be challenging as standardized protocols have not yet been developed. The objective of this study was to identify culture conditions, including antibiotic supplementation, biopsy size, and culture temperature, suitable for establishing primary cell cultures of ngege (Oreochromis esculentus), a critically endangered African cichlid. Six-millimeter caudal fin biopsies provided sufficient material to develop a primary cell culture when incubated at 25°C using standard fish cell culture medium containing 1× Primocin. Further investigation and application of these culture conditions for other endangered freshwater fishes is necessary.     

Two new genera and species of the subfamily Brosmophycinae (Bythitidae,Ophidiiformes) from Northern Australia

Two new bythitid genera and species of the subfamily Brosmophycinae are described from Northern Territory, Australia.Brosmolus longicaudus, described from a single male specimen, is unique in the tribe Brosmophycini in having the anal fin origin well anterior to the midpoint of the body and thin, transparent skin on the head and body.Beaglichthys macrophthalmus, described from a single female specimen, differs from all other genera in the subfamily by the following combination of characters: eight branchiostegal rays, eye diameter longer than snout length, cheek scaly, anal fin origin at midpoint of body, three developed rakers on the first gill arch, 12 caudal fin rays, and 14 precaudal vertebrae.     

乐山棒花鱼形态特征的两性异形和雌性个体生育力

测定了乐山棒花鱼(Abbottina kiatingensis)繁殖期形态特征包括体长、头长、头宽、头高、吻长、眼后头长、眼径、眼间距、体高、尾柄长、尾柄高、尾鳍长、背鳍基前距、背鳍基长、腹鳍基前距、腹臀间距、体重和去内脏体重的两性异形和雌性个体生育力。繁殖期雄性个体的数量显著多于雌性个体,雌雄两性个体的体长差异不显著。特定体长的雌性个体的头长、头宽、头高、吻长、眼后头长、尾柄高、背鳍基前距、背鳍基长和去内脏体重显著小于雄性个体,其余指标不存在明显的差异。回归分析表明,乐山棒花鱼的怀卵数量与体长和体重回归关系显著,雌性通过个体大小(体长和体重)的增加来提高个体生育力。     

Loaches of the genus Lepidocephalichthys, from Manipur, with description of a new species

A new species Lepidocephalichthys manipurensis , is described, confined to the Chandel district of Manipur near the adjoining borderland areas of Manipur, India and Burma (Myanmar). It is distinguished by the following combination of characters: a sharp small black dot just above the upper base of the caudal fin; 8–9 dorsal short dark ashy brown bars from occiput to the base of the caudal fin; absence of scales on the vertex of head; caudal fin fork, pectoral, ventral and anal fins are non-immaculate; least depth of caudal peduncle 50·00–60·24% (mean 54·09) of its length and 7·69–8·11% L , S (mean 8·22); caudal fin with 4–5 W-shaped bands: a single dark black stripe from tip of snout to eye; 8–11 spots on the mid lateral line; and 30–31 vertebrae. A key to the identification of lepidocephalid loaches of Manipur is provided.     

Gymnocranius superciliosus and Gymnocranius satoi, two new large-eye breams (Sparoidea: Lethrinidae) from the Coral Sea and adjacent regions

Two related perciform fish species of the subfamily Monotaxinae (Sparoidea: Lethrinidae) Gymnocranius superciliosus sp. nov. and Gymnocranius satoi sp. nov. are described from specimens and tissue samples from the Coral Sea and adjacent regions. G. superciliosus sp. nov. is distinct from all other known Gymnocranius spp. by the following combination of characters: body elongated (depth 2.7–3.1 in standard length), caudal fin moderately forked with a subtle middle notch, its lobes slightly convex inside, distinctive blackish eyebrow, snout and cheek with blue speckles, and dorsal, pectoral, anal and caudal fins reddish. G. satoi sp. nov. is the red-finned ‘Gymnocranius sp.’ depicted in previous taxonomic revisions. While colour patterns are similar between the two species, G. satoi sp. nov. is distinct from G. superciliosus sp. nov. by the ratio of standard length to body depth (2.4–2.5 vs. 2.7–3.1) and by the shape of the caudal fin, which is more shallowly forked, its lobes convex inside and their extremities rounded. The two species are genetically distinct from each other and they are genetically distinct from G. elongatus, G. euanus, G. grandoculis, and G. oblongus sampled from the Coral Sea and adjacent regions.     

Genome-Scale Association Study of Abnormal Scale Pattern in Yellow River Carp Identified Previously Known Causative Gene in European Mirror Carp

Common carp (Cyprinus carpio) is one of the most widely studied fish species due to its great economic value and strong environmental adaptability. Scattered scale, a typical phenotype of the mirror carp that is derived from Europe, has never been observed in the Yellow River carp previously. We recently identified approximately one fourth of the F1 progenies displaying scattered scale in a full-sib Yellow River carp family in our breeding program, despite both parents that showed wild type with normal scale patterns. This family provides us unique materials to investigate the genetic basis underlying the abnormal scale mutant in Yellow River carp population. Genome-wide association study (GWAS) and association mapping were performed based on genome-wide single nucleotide polymorphisms (SNP) genotyped with common carp 250 K SNP genotyping array in 82 samples of the Yellow River carp family. We identified a 1.4 Mb genome region that was significantly associated with abnormal scattered scale patterns. We further identified a deletion mutation in fibroblast growth factor receptor 1 a1 (fgfr1a1) gene within this genome region. Amplification and sequencing analysis of this gene revealed a 311-bp deletion in intron 10 and exon 11, which proved that fgfr1a1 could be the causal gene responsible for abnormal scattered scale in the Yellow River carp family. Since similar fragment mutation with 306-bp and 310-bp deletions had been previously reported as causal mutation of scattered scale patterns in the mirror carp, we speculate that either the deletion mutation was introduced from Europe-derived mirror carp or the deletion independently occurred in the mutation hotspot in fgfr1a1 gene. The results provided insights into the genetic basis of scale pattern mutant in Yellow River carp population, which would help us to eliminate the recessive allele of the abnormal scale patterns in Yellow River carp population by molecular marker-assisted breeding.     

A New Lanternshark <Emphasis Type="Italic">Etmopterus splendidus</Emphasis> from the East China Sea and Java Sea

A new species of the lanternshark Etmopterus splendidus is described. This new species is distinguished from the congeners by the combination of the following characters: distance from snout tip to 1st dorsal spine much less than distance from the spine to upper caudal origin; caudal fin short, much less than head length; dermal denticles on lateral side of trunk with very small, erect thornlike, conical crowns, those on trunk arranged in regular longitudinal rows, and distinctly arranged on interdorsal area and on lateral trunk of interspace between 2nd dorsal and caudal, but not arranged in regular longitudinal rows on dorsal surface of interorbital and o abdomen; color in life purplish-black above and with inconspicuous bluish-black flank marks and three other bluish-black marks at base of caudal fin and along its axis; shape of flank marks narrow anterior to, but broader posterior to pelvic fins.