Total Number Of Vertebrae Research Articles

Osteological variation in the spectacled porpoise (Phocoena dioptrica)

Cranial and post-cranial variation is described for a large series of specimens of spectacled porpoise from Argentina and compared with that for specimens from other areas of the Southern Hemisphere. Condylobasal length in 54 adult skulls was 276-424. Tooth counts were 16-26 and 17-23 in the upper and lower jaws, respectively. Total number of vertebrae (n = 20) was 66-70. The rostrum may be relatively smaller in the Auckland Islands than in other regions.

Spine Anomalies and Vertebral Phenotypes in the Underyearlings of Roach Rutilus rutilus (Cyprinidae) after Separate and Combined Exposure to a Magnetic Field and Metrifonate on Embryos

Anomalies in the spine structure and vertebral phenotypes were studied in 4-month-old underyearlings of the roach Rutilus rutilus (Linnaeus, 1758) after combined or separate exposure of embryos to a magnetic field (frequency 500 Hz, induction 150 μT) and metrifonate (concentration 0.01 mg/L) for 48 h from fertilization to the onset of organogenesis in comparison with control (no treatment). The most common developmental disorders of the spine in all groups are open neural or haemal arches, as well as deformities and fusions of the vertebra bodies. An increase in the total number of vertebrae and their number in the trunk section of the spine were noted in fish with vertebra fusions. Juveniles under treatments differed from those in control by a greater number of spinal anomalies, as well as by the frequency of occurrence of specific vertebral phenotypes. The magnetic field had the greatest effect.

New data on tail lengths and variation along the caudal series in the non-avialan dinosaurs.

The tails of non-avialan dinosaurs varied considerably in terms of overall length, total number of vertebrae, and gross form and function. A new dataset confirms that there is little or no consistent relationship between tail length and snout-sacrum length. Consequently, attempts to estimate one from the other are likely to be very error-prone. Patterns of changes in centra lengths across the caudal series vary among non-avian dinosaurs. However, some overarching patterns do emerge. A number of taxa show (anterior to posterior) a series of short centra, followed by a series of longer centra, with the remainder of the tail consisting of a long series of centra tapering in length. This pattern is consistent with functional constraints, and the anterior series of longer centra are coincident with the major attachments of femoral musculature. This pattern is not present in many basal taxa and may have evolved independently in different dinosaurian groups, further suggesting functional importance.

Axial skeleton morphology of the Western Palearctic aphaniid fishes (Teleostei: Cyprinodontiformes; Family: Aphaniidae)

AbstractThe axial skeleton morphology of eighteen aphaniid species was examined for the first time by X‐ray radiography, a non‐lethal method. The number of total vertebrae in the genus Aphanius is ranged from 26 to 29, in Aphaniops, it is ranged from 24 to 28, and in Paraphanius mento, it is ranged from 26 to 27. The vertebral column in Aphanius was often slightly curved, and it is varied from almost straight (most common) to slightly or strongly curved and straight in two others. The caudal skeleton of the family Aphaniidae is characterized by a single and completely fused hypural plate, and a total number of 9–12 branched segmented soft rays, a single and elongate epural bone. All examined species of the genus Aphanius and Paraphanius mento displayed a straight epural bone in their caudal skeleton, while it was often sinuous‐like and thick in all species of the genus Aphaniops. This study supports the assumption that a sinuous epural is likely the first detected morphological synapomorphy for the “inner” clade of Aphaniops. The family Aphaniidae is closer to Cyprinodontidae, Valenciidae and Fundulidae than other cyprinodontiforms in the caudal skeleton, which is in agreement with the multigene phylogeny of cyprinodontiforms.

Deformities prevalence in farmed ballan wrasse (Labrus bergylta) in relation to hatchery origin and life stage

The production of farmed ballan wrasse (Labrus bergylta) is developing, with an emphasis on sustainability and quality. However, ballan wrasse hatcheries have anecdotally reported increased prevalence of malformations which may impact on fish welfare and hatchery productivity. The present study therefore aimed to identify and characterise deformities in two of the largest ballan wrasse producers in the UK. A total of 384 farmed fish were sampled at two life stages (post-weaning and pre-deployment) and independent production runs. Additionally, 25 wild caught ballan wrasse were analysed and used as a reference. Each fish was externally examined for malformations including jaw and operculum deformities. The fish were internally examined by x-ray for vertebral deformities and abnormalities of the swim bladder. Mineral analysis of both whole fish and vertebrae were also conducted. The results showed the first information on the ballan wrasse skeleton structure. The total number of vertebrae per fish ranged from 34 to 37, with 37 vertebrae per fish representing 58.2% of all fish analysed. The vertebral column was divided into two regions, namely R1 and R2. R1 included vertebrae 1 to 17 (post-cranial and pre-haemal vertebrae) while R2 included vertebrae 18 to 34–37 (haemal vertebrae and haemal caudal vertebrae). Results showed a high prevalence of vertebrae malformations (up to 33%), jaw/operculum malformations (up to 13.5%) and nephrocalcinosis (up to 25%), with high severity levels in some cases when compared to wild specimens in which malformations were absent. Most malformations were already visible at post-weaning. Wild fish did not show signs of any malformations. Finally, high mineral diets are suggested as a potential route of investigation to reduce the vertebral deformities in ballan wrasse. Increasing the productivity of cleaner fish hatcheries is key to addressing the on-going challenge of sea lice in Atlantic salmon (Salmo salar) farming. It is therefore of paramount importance that the causes of the presently identified pathologies are confirmed and mitigation steps introduced.

A Description of Chirolophis japonicus and Ch. saitone (Stichaeidae) Pelagic Larvae from Peter the Great Bay, Sea of Japan

The larval development of Chirolophis japonicus and Ch. saitone from the yolk-sac stage to the settlement on the bottom is described from waters of Peter the Great Bay, Sea of Japan. The pattern of distribution of melanin pigmentation over the body of larvae in these Chirolophis species is formalized for the first time. It consists of six rows, the aggregation on the top of head, and several single melanophores. Despite the similarity between the species, each of them has its specific features that are manifested mainly as a different number of axial skeleton elements (total number of vertebrae and number of rays in the dorsal and anal fins). A conclusion is made that a reliable diagnostic character to identify larvae of Ch. japonicus and Ch. saitone within the period of their development from hatching to settlement can be the number of melanophores at the base of the anal fin rays.

Skeletal determinants of tail length are different between macaque species groups

Macaques (genus Macaca) are known to have wide variation in tail length. Within each species group tail length varies, which could be associated with a phylogenetic trend seen in caudal vertebral morphology. We compared numbers and lengths of caudal vertebrae in species of the fascicularis group, M. assamensis (sinica group), M. nemestrina (silenus group), and those obtained from reports for an additional 11 species. Our results suggest different trends in number and lengths. The caudal vertebral length profiles revealed upward convex patterns for macaques with relative tail lengths of ≥15%, and flat to decreasing for those with relative tail lengths of ≤12%. They varied between species groups in terms of the lengths of proximal vertebrae, position and length of the longest vertebra, numbers and lengths of distal vertebrae, and total number of vertebrae. In silenus and sinica group, the vertebral length is the major skeletal determinant of tail length. On the other hand, the vertebral number is the skeletal determinant of tail length in the fascicularis group. Tail length variation among species groups are caused by different mechanisms which reflect the evolutionary history of macaques.

Meristic, morphometric and biological characteristics of the common moray eel (Muraena helena) in northern Tunisia

AbstractAlthough common in the Mediterranean, the morphological and biological characteristics of the moray eel Muraena helena are largely unknown. This study, based on 310 specimens caught using a longline at a depth of 50–100 m, addresses this knowledge gap for northern Tunisia, which is a stronghold of the species. There were significantly more males than females, with a sex ratio of 1:1.5. The number of vertebrae between individuals were variable, especially abdominal and caudal vertebrae (range 56–72; 70–84, respectively). Overall, the total number of vertebrae was less variable (138–146 ± 3.6 SE) and similar between males and females. The length-length relationship recorded for M. helena is provided for the first time, with the pre-anal length (paL), pre-dorsal length (pdL) and the head length (hL) growing faster than the total length (TL). According to the weight-length relationship (WLR), positive allometric growth was established for males (b = 3.6), females (b = 3.46) and combined sexes (b = 3.54). The relative condition factor (CF) did not show significant differences between seasons. The gonadosomatic index (GSI) indicated a significant difference between the seasons for females, whilst the hepatosomatic index (HSI) highlighted a significant difference between seasons for both males and females.

Temperature sensitive regions of the Chinook salmon vertebral column: Vestiges and meristic variation.

Variation of vertebral centra numbers is common in vertebrates. Likewise, the number of associated elements such as ribs and neural and haemal arches can vary and affect all regions of the vertebral column. In mammals, only the number of cervical vertebrae is invariable. Variation of total vertebral centra numbers is well documented in teleost fish, often related to temperature. Less information is available about which part of the vertebral column and which associated elements are liable to variation. Here, variation in number of vertebral centra and associated elements is studied in Chinook salmon in six distinct anatomical regions. Animals are raised at 8 and 12°C to ask whether the vertebral centrum numbers, the pattern, and the frequency of variation in particular regions are temperature dependent. No significant difference concerning the total number of vertebrae was found, but regional differences occurred between the 8 and 12°C groups. Twelve specimens out of 60 of the 12°C group had three postcranial vertebrae compared to only one specimen in the 8°C group. The number of transitional vertebrae is significantly different in 8 and 12°C specimens. Fewer transitional vertebrae occur in more anterior positions in 8°C specimens. Most specimens of both temperature groups had two ural centra; however 17 specimens out of 60 of the 12°C group had up to five ural centra. Specimens of the 12°C group show more variation in the presence of the vestigial ribs associated with transitional vertebrae. Clearly, the postcranial, transitional, and ural regions are temperature sensitive. This study shows that nonsignificant differences in the total number of vertebrae can mask significant regional variation. Variation of vertebral numbers could be the consequence of loss or gain of vertebral centra and/or a change in the identity of the associated element on the vertebral centrum.

A new species of Hemibrycon (Characiformes, Characidae, Stevardiinae) from the upper Magdalena River basin in Colombia.

Hemibrycon iqueima sp. nov., is described from small streams in the Magdalena drainage at the foothills of the western slope of the Eastern Cordillera of the Colombian Andes, Suarez municipality, Tolima Department, Colombia. The new species is distinguished from its congeners in the Magdalena-Cauca River basin by a combination of characters related to snout-anal-fin origin length, head length, dorsal-pectoral fin distance, dorsal-fin-hypural distance, postorbital distance, orbital diameter, snout length, number of total vertebrae, pre-dorsal scales, scale rows between anal-fin origin and lateral line, number of branched rays of the anal fin, maxillary teeth number and number and arrangement of hooks on the branched rays of the pectoral and dorsal fins. In addition, the validity of this species is supported by previous molecular analyses that included specimens of the new species that had been erroneously identified. Phylogenetic relationships between the new species and congeners from Pacific coast basins are discussed.

Influence of blood supply on fracture healing of vertebral bodies.

The relevance of blood supply for bone fracture healing has been discussed throughout the literature, using scaphoids as the most referred to. But, there is virtually nothing known about the relevance of blood supply for the vertebral fracture healing and even the guidelines of AO do not deal with this issue. A prospective cohort study of 107 patients was run from January 2016 to December 2016, with 54 male and 53 female patients, who were treated for traumatic vertebral fractures of thoracolumbar spine using posterior stabilization only. The average age was 67years and the follow-up 12.3weeks. The total number of vertebrae was 129. We analyzed the fracture morphology and measured the vertebral bodies in all three dimensions, with five reference planes. The progress of vertebral deformity in time measured before and after the surgery was correlated with the potential damage of the main vascular canal in the rear of each vertebral body. The bone pattern and morphology were analyzed in detail as well. Pathological fractures were not taken into our consideration. The overall deformity progression of vertebral bodies in the fractures with morphologically damaged blood supply was in all measured dimensions significantly higher than in the fractures with supposedly maintained perfusion. The osteoporosis played its role as well, but only with medium effect size compared with strong effect size of the vessel canal damage (Cohen). The combination of the both factors (damage to the vessel canal together with osteoporosis) showed also a strong correlation with a relevant deformity progression (Evans), but not much different from the vessel canal damage alone. With regard to the relevant changes of the vertebral body dimensions/volume, we found relevant changes in 52% of all fractures (SD 0.5017) generally, for the subgroup with the canal damage in 84% (SD 0.3691), with strong correlation (Evans, 0.7721). In the group of fractures with maintained perfusion, we found such changes in only in 5% of fractures (SD 0.2333). For decision making, we should take mechanical fracture analysis and dynamic processes within traumatized tissue a part of whose is the blood supply and oxygenation into surgical consideration. We recommend anterior rather than posterior stabilization for the cases with damaged vessel canal, and the vertebroplasty could pose an alternative in the elderly.

The first description of the juvenile Davidijordania lacertina (Pavlenko, 1910) (Perciformes: Zoarcidae)

The article provides a description of Davidijordania lacertina (Pavlenko, 1910) with a body length of 18.0–32.0 mm TL, collected from Vostok Bay, Sea of Japan. The total number of vertebrae (119–121) and the pigment pattern on the bodies of the examined juvenile fish correspond to those of D. lacertina.

Morphological variation among geographic populations of the rare finless eels Apterichtus anguiformis and Apterichtus caecus (Anguilliformes: Ophichthidae)

Morphological analysis of recently collected specimens of the slender finless eel Apterichtus anguiformis (26 specimens) and the European finless eel Apterichtus caecus (14 specimens) in waters off the coast of Sardinia (central-western Mediterranean) confirmed their distinction from each other. Analysis also revealed a pronounced difference in mouth length in A. anguiformis from Sardinian waters when compared to the holotype and published data.To clarify their taxonomic status, morphological characteristics of the finless eels were analysed using morphometric and meristic characters. The morphometric differences between species were mainly related to the position of the anus and to cranial-related characters. Variation in meristic traits revealed differences in the number of operculum and pre-anal pores as well as the number of total vertebrae. Finally, we were able to capture specimens of these rare species using experimental trawl fishing gear, in which the entire cod-end was covered with a fine mesh net size of 8 mm; this sampling approach would be a good sampling method for further studies.

Delayed consequences of extremely low-frequency magnetic fields and the influence of adverse environmental conditions on roach Rutilus rutilus embryos.

This study presents data collected over a 6 year period on the effects of extremely low-frequency magnetic fields (MFs) (1.4-1.6 µT, 500 Hz and 1.4-1.6 µT, 72.5 Hz) and MFs in combination with other environmental stressors (elevated temperature, 0.01 mg l(-1) trichlorfon, 0.01 mg l(-1) copper sulphate pentahydrate) on roach Rutilus rutilus embryos. Effects were studied during different stages of early development. Rutilus rutilus were raised in ponds for 4 months after exposure to MFs. The mass, standard length (LS ) and morphological characteristics of underyearlings which were exposed as embryos were recorded. An increase in embryo mortality and a decrease in LS and mass indices in underyearlings were noted after they had been exposed to a combination of MFs and different adverse environmental factors. In addition, exposure to MFs led to changes in the total number of vertebrae and the number of seismosensory system openings in the mandibular bones of underyearlings. MFs of different frequency caused both increases (500 Hz) and decreases (72.5 Hz) in morphological diversity. The stressors used in this study, however, did not increase the fluctuating asymmetry of bilateral morphological characteristics. The possible microevolutionary effects of exposure to MFs alone and in combination with other adverse environmental factors upon natural fish populations are discussed.

Biometry of Bagrid Fish Mystus pelusius (Solander, 1794) (Siluriformes: Bagridae) from Al-Hammar Marsh, Southern Iraq

A total of 41 specimens of bagrid fish Mystus pelusius (Solander, 1794), were collected from Al-Hammar marsh, southern Iraq during December 2011 till April 2012. Meristic and morphometric characters are given. Dorsal fin containing one strong spine and 6-8 rays, anal fin 9-12 rays, total gill raker 14 on first gill arch. dorsal fin base length 14.3-16.1, Anal fin base length 9.8-13, inter dorsal - adipose fin distance 3.7-6.7, Adipose fin base length 39.3-45.2, Caudal peduncle length 19.9-26.2, Pre Anus length 49.2-55.1, all in percentage of standard length. Head width 65.19-78.2, post orbital length 42.23-47.88, eye diameter16.89-19.45, dorsal spine length 71.75-92.18, maxillary barble 201.34-245.83, and nasal barble 35.43 - 54.2 all in percentage of head length. Total number of vertebrae 44-46.

Notes on the congrid eel genus Parabathymyrus from the western Pacific Ocean, with the description of a new species (Pisces: Anguilliformes: Congridae).

The congrid eel genus Parabathymyrus from the western Pacific Ocean is reviewed and three species are recognized: Parabathymyrus macrophthalmus from Japan, Taiwan, Vietnam and Australia, P. brachyrhynchus from Taiwan, Vietnam, the Philippines, Vanuatu and Solomon Islands, and a new species, P. philippinensis sp. nov., is described based on two specimens collected from the Philippines. These three species can be distinguished from each other by the number of total vertebrae (128-137 in P. macrophthalmus, 162-173 in P. brachyrhynchus and 140-141 in P. philippinensis sp. nov.), preanal vertebrae (39-46, 49-58, and 42), preanal lateral-line pores (36-44, 46-54, and 40-42), total lateral-line pores (121-131, 159-169, and 140-141) and supraorbital pores (4, 4 and 3).

Investigation of Surgery Characteristics in Patients with Spondylolisthesis, Rasht, Iran from 2006 to 2011

Background & Aim: Spondylolisthesis is a visible deformity in lumbosacral region with vertebral slip and fracture or other deformities of pars interarticularis. This study aims at investigating the characteristics of spondylolisthesis surgery in operated patients. Methods & Materials/Patients: This is a retrospective study which included all the patients who had undergone spondylolisthesis surgery by one same surgeon from 2006 to 2011. Demographic characteristics such as age, gender, and surgery information including type of spondylolisthesis, incision site, laminectomy site, foraminotomy site, fixation site of vertebra and site of vertebral disc evacuation were collected. The data were analyzed using SPSS (Version16). Results: 52 of 63 enrolled patients were women (82.5%) and 11 men (17.5%) with mean age of 49.6 years. Based on frequency, spondylolisthesis types were 60 degenerative (95.2%), 2 post-surgical (3.2%) and 1 post-traumatic (1.6%), respectively. 58 patients had spondylolisthesis only in one vertebra and 5 patients in two vertebrae. The total number of slipped vertebrae was 68, in which slip was seen in L3, L4 or L5 vertebrae. In 42 patients, laminectomy was performed only in one vertebra, in 19 patients in two vertebrae, in 1 patient in three vertebrae and in 1 patient in five vertebrae. The total number of vertebrae with foraminotomy was 106. The highest frequency of foraminotomy was seen in L5, L4, and S1 vertebrae, respectively. Except in one case, the rest 62 patients underwent fixation surgery in two or three vertebrae. Conclusion: Based on the results, the frequency of spondylolisthesis was approximately five times in women compared to men. The most common type was degenerative spondylolisthesis. Type of surgery was fixation with pedicle screw and fusion.

New species of the genus Ariosoma, A. dolichopterum (Bathymyrinae), from the waters of Central Vietnam

A new species, Ariosoma dolichopterum is described from 30 specimens collected in the coastal waters of Central Vietnam. This species differs from a related species A. anago in lower total number of vertebrae (127–131), lower number of precaudal vertebrae (58–61) and preanal pores (46–50), and larger length of the pectoral fins (39–48% of head length). The distribution of adult and larval forms of this species of congrid eels (Bathymyrinae) in the South China Sea and adjacent waters of western Pacific is given.

Osteology and Cartilaginous Elements of Trilepida salgueiroi (Amaral, 1954) (Scolecophidia: Leptotyphlopidae).

Morphological and anatomical studies on the Leptotyphlopidae have increased in the past 10 years, providing important data on the systematics of this group, mainly focused on the skull and lower jaw morphology. However, most studies are based on a single specimen, rarely combining more than one single method of assessing morphological information. Therefore, several data on postcranial morphology, sexual dimorphism, and ontogenetic and intraspecific variation of leptotyphlopids remain poorly understood. Herein, we provide a detailed description of the cranial and postcranial skeleton of Trilepida salgueiroi based on more than 20 specimens (including males, females and juveniles), as well as a description of osteology and cartilaginous elements through the use of combined methodologies such as X-ray scanning, high resolution CT-scanning, and clearing and staining of articulated and disarticulated specimens. We also provide data on the presence/absence of dimorphic and intraspecific variation of the observed characters. The presence of a statolithic mass in the cavum vestibuli differs from the pattern found in other scolecophidians. A correlation of dorsal vertebrae with ventral and subcaudal scales was found (1:1), as well as total number of vertebrae with middorsal scales (1:1), thoracolumbar vertebrae and ventral scales (1:1), and a higher number of caudal vertebra with subcaudal scales (1.23:1). Intraspecific variation was found in several elements of the skull, lower jaw, pelvic girdle and vertebral number, but no evidence of sexual dimorphism was found in any of the species characters analysed. The homologies of several elements are discussed, although still remaining poorly understood and unknown.

New Record of Scolecenchelys fuscogularis (Anguilliformes: Ophichthidae) Leptocephali from Korea, as Revealed by Morphological and Molecular Analyses

Three leptocephali (22.2, 22.7, 56.0 mm in total length) collected from the East/Japan Sea were identified by morphological and genetic analyses as belonging to the genus Scolecenchelys (Anguilliformes, Ophichthidae). Morphologically, the specimens were characterized by 148-158 myomeres, 10 gut swellings, dorsal fin origin above middle of the body, and 6 postanal melanophores between the anus and the caudal margin. An analysis of an 849-base pair 12S rRNA sequence of mitochondrial DNA showed that sequences are concordant with those of adult Scolecenchelys fuscogularis (genetic distance = 0.001). Furthermore total number of myomeres is consistent with the total number of vertebrae in adult S. fuscogularis. This study provides the first description of the morphological characteristics of S. fuscogularis leptocephali and their variations with size. The Korean name of S. fuscogularis is “Ga-neun-mul-baem”, established by Ji et al. (2012).