Dorsal Spine Research Articles

Scanning electron microscopy, morphometric and energy dispersive X-Ray analysis of cephalothoracic structures exploring defensive and sensory features in kuruma shrimp (Marsupenaeus japonicus Spence Bate, 1888)

Abstract Background Kuruma shrimp (Marsupenaeus japonicus) is a commercially important crustacean and a valuable global food source. This study employed scanning electron microscopy (SEM) to explore the morphology and morphometric features of the Marsupenaeus japonicus cephalothoracic structures, including antennules, antennas, scaphocerite, rostrums, and eye stalks. The primary focus was on understanding the role of each part, especially through the examination of setae, which are crucial for chemoreception and defense. Additionally, energy dispersive X-ray spectroscopy (EDX) analysis was utilized to identify the elemental composition of these structures. Material and methods The samples from the heads of fifteen Marsupenaeus japonicus were studied by gross morphology and morphometry, SEM, and EDX analysis. This study is the first to integrate both SEM and EDX techniques for a detailed analysis of these cephalothoracic structures, offering an innovative approach to understanding both morphological and elemental characteristics. Results Marsupenaeus japonicus exhibited two antennules and two antennae. The antenna featured four basal segments: basicerite, ischiocerite, merocerite, and carpocerite, each with distinctive articulations and setae distribution. The antennule, with three segments covered by plumose setae, displayed curved cone-shaped flagellae. The scaphocerite, resembling a paddle, showcased plumose setae, while the rostrum exhibited dorsal and ventral spines, lateral grooves, and unique setal arrangements. Setal measurements across structures revealed diverse lengths and widths, indicating functional specialization. The compound eyes were connected to an optic stalk adorned with plumose setae. EDX analysis revealed higher percentages of calcium and phosphorus in the spear-like structures of the scaphocerite, rostrum, and antenna, respectively. Conclusion This investigation provides a thorough examination of the intricate morphological features of the cephalothoracic region of Marsupenaeus japonicus, shedding light on its sensory and defensive capabilities. The novel application of both SEM and EDX not only deepens our insights into these structures but also lays the groundwork for future studies using this dual approach to explore crustacean morphology, with potential advantages for sustainable aquaculture and the conservation of marine ecosystems.

Growth patterns and age determination of Piked Dogfish from Romanian Black Sea waters: Insights from spines analysis

Understanding the growth patterns and the age composition of Squalus acanthias (piked dogfish) populations, from Romanian marine area, helps to elaborate sustainable fisheries management practices because changes in population parameters could indicate shifts in prey availability, habitat quality issues, or fishing pressure. In recent years, the official catches on the Romanian coast, of this economically valuable species in the entire Black Sea basin, have remained below one ton. Regarding the growth patterns, a slight increase in the average length value was observed, from 107,85 cm in 2022 to 116,88 cm in 2023. For age determination the method of analyzing the dorsal spines was used, considered the most appropriate. Thus, in 2022 mature specimens (19 years old) predominated, and in 2023, younger specimens (14 years old), but completely mature from a reproductive point of view, predominated. Analyzing age structure over time is important for predicting future population trends and implementing conservation measures as needed.

Age and length characteristics of female and male Walleye broodstock collected at a spawning operation

AbstractObjectiveThe need to augment of Walleye Sander vitreus populations may increase as these populations face challenges of changing habitats and climatic conditions. Since little has been published outside of agency reports on wild broodstocks, the intent of this study was to describe sex‐specific Walleye spawning participation from a Great Plains broodstock operation. Specific objectives will assess standardization to collect target number of broodstock effort, catch per unit effort, and length and age participation of female and male broodstock.MethodsWalleye were collected at Sherman Reservoir, Nebraska, during April spawn collection operations from 2015 to 2019. Gill nets were used to collect female Walleye, and boat electrofishing was used to collect male Walleye. Catch per effort was calculated for each sex, fish were measured to nearest 1‐cm length‐group, and a dorsal spine was taken from a subset of fish per length‐group. Mean lengths and ages were calculated for each year of the study. Data were combined for all years of the project to display percent contribution by length and age.ResultThe amount of effort to capture 100 female and male Walleye varied by 4× and 2.5×, respectively, over the 5 years of sampling. Mean lengths and ages (±SE) of female (65 ± 1 cm; 10.4 ± 0.1 years) and male (43 ± 1 cm; 6.3 ± 0.1 years) Walleye collected were consistent during this study. The female Walleye collected represented 14 different ages, but ages 9–12 comprised 66% of all captured broodstock. The collected male Walleye also demonstrated age‐compressed spawning tendencies, with ages 4–7 accounting for 74% of collected individuals that represented 13 different ages.ConclusionThese results can define the anticipated variability in catch that can be expected at broodstock collection operations along with connection to specific lengths and ages of Walleye. Additionally, recognition that female and male Walleye broodstock contributions are consistently coming from four specific ages that are not the same year‐classes may allow spawning operation staff to anticipate brood availability and ultimately improve the planning efficiency of these operations.

Chronic nonbacterial osteomyelitis in neuroradiology - behavior and evolution of vertebral and mandibular lesions on imaging.

Chronic nonbacterial osteomyelitis (CNO) is a rare non-infectious inflammatory musculoskeletal disease where imaging plays a key diagnostic role. Vertebral and mandibular lesions are frequent manifestations, meaning their awareness is crucial for the neuroradiologist to avoid delays in diagnosis and treatment. Characterize vertebral and mandibular CNO lesions on imaging to assist practicing neuroradiologists in better identifying this disease. Retrospective review of all CNO patients of our pediatric center, including only patients with vertebral or mandibular lesions. All imaging exams were analyzed to record lesion characteristics. We included 13 patients (six male). The mean age of onset was 12.3years. Ten patients had only vertebral lesions, two had only mandibular lesions, and one had both. For patients with vertebral lesions, the median number of levels affected was three, 81.8% had multiple levels affected, 90.0% had dorsal spine lesions, 72.7% had platyspondyly, and 81.8% had inflammatory changes. All vertebral lesions had at least partial resolution of inflammatory findings, the mean time of lesion activity was 2.5years, and recurrence occurred in 27.3%. Three patients had sacral lesions, all with sacroiliitis. In patients with mandibular lesions, all had unilateral lesions involving the mandibular ramus, all had hyperostosis, periosteal reaction, bone edema, and soft tissue inflammation, all had partial resolution on follow-up, and one had recurrence. CNO vertebral lesions are not rare, are often multiple, predominantly affect dorsal levels, and most result in vertebral height loss. Resolution of vertebral inflammatory lesions is frequent, but so is recurrence. Sacral lesions may be present and result in sacroiliitis. The mandible may be a site of unifocal disease, typically affecting the ramus, with prominent bony changes and soft tissue inflammation.

Clinical Profile and Surgical Management of Intramedullary Spinal Cord Tumors

Background and Aim: Intramedullary spinal cord tumors (IMSCTs) are rare tumors of the spine. The study aims to analyze the clinical profile and surgical management of IMSCTs. Methods and Materials/Patients: This is a retrospective study to review the IMSCTs operated between January 2007 to December 2021. Myxopapillary ependymomas were excluded from the study. Results: There were twenty-seven operated cases of IMSCTs. The Mean±SD age was 39±22 years. Fifteen (55.5%) were males and 12(44.5%) were female patients. There were 6(22%) cervical, 7(26%) cervicodorsal, 9 (33%) dorsal, and 5(19%) dorsolumbar IMSCTs. The Mean±SD duration of symptoms was 10±14 months. Ten (37%) patients had spinal cord syrinx. Motor weakness and pain were the most common symptoms. Intraoperative gross total resection (GTR) was achieved in 12(44.4%) patients, near-total resection in 4(14.8%) patients, subtotal resection in 2(7.4%) patients, decompression in 7(26%) patients, and biopsy in 2(7.4%) patients. Eighteen (66.6%) patients had neurological status same as preoperative status. Four (14.8%) patients had improvement and 5(18.5%) patients had deterioration in neurological status. Ependymoma was the most common histological type of IMSCT (40.5%). Other lesions are glioma, hemangioblastoma, lipoma, schwannoma, lymphoma, capillary hemangioma, arachnoid cyst, and epidermoid cyst with spinal dysraphism. Ependymomas had well-defined margins compared to other gliomas. Duration of stay in the hospital was 9±3.5 days. Conclusion: Dorsal spine is the most common location of IMSCTs and ependymoma is the most common histological type. It is the surgeon’s intraoperative decision regarding the extent of resection of the tumor based on the spinal cord infiltration and tumor type. GTR is possible in the majority of ependymomas and some other histological tumors like schwannoma, arachnoid cyst, and epidermoid cyst.

Infected Primary Bone Mantle Cell Lymphoma with Multiple Vertebral Involvement

Primary vertebral lymphoma is an exceedingly rare entity. We hereby report a case of a 67-year-old male who presented to our department with fever, weight loss, and progressively worsening lower back pain radiating to the right hip. Physical examination showed pain on percussion of the dorsal and lumbar spine and tenderness on palpation of the right upper thigh area. The radiographic findings revealed numerous vertebral lesions with a right psoas abscess extending to the right upper thigh. Intravenous antibiotic therapy was initiated and the patient underwent an incision and drainage of the psoas abscess with a favourable outcome. However, given the suspicious imaging findings of the osseous lesions suggestive of malignancy, a vertebral biopsy was performed and yielded histo-pathological findings consistent with bone mantle cell lymphoma. To the best of our knowledge, this is the first case of an infected primary bone mantle cell lymphoma with multiple vertebral involvement. The diagnosis is challenging and can be confused with other diseases.

Fish That Fish for Fish-A Peculiar Location of "Fishing Motoneurons" in the Striated Frogfish Antennarius striatus.

In lophiform teleosts, the first dorsal fin has evolved as a specialized structure called the "illicium" equipped with the esca, which is a modified skin flap used to attract small fish for predation. The motor control system of the illicium, however, remained unknown. The present study investigated the innervation of muscles for the illicium and morphology of motoneurons innervating them in the striated frogfish Antennarius striatus. We found that the dorsal ramus of occipital nerve innervates the muscles. Motoneurons for the illicium are present in the dorsolateral zone of ventral horn at the medullo-spinal boundary level, forming a cluster somewhat distinct from other motoneurons of the ventral horn. Motoneurons for the second to fourth dorsal fins and pectoral fin were located in the ventrolateral and ventromedial zones of ventral horn, respectively, whereas those of the dorsal trunk muscle in the dorsomedial zone of ventral horn. Motoneurons for the first dorsal spine of white-spotted pygmy filefish were also investigated for species comparison and were found to locate in the ventrolateral zone of ventral horn, similarly to the motoneurons for the second to fourth dorsal fins of the frogfish. These results suggest that motoneurons for the illicium have become segregated from other motoneurons to be situated in an unusual dorsal position for a motoneuron pool of a dorsal fin, in concert with the evolution of specialized "fishing behavior" performed by the illicium.

Septic paravertebral abscess and inferior vena cava thrombosis complicated by uro-sepsis: Case report

Paravertebral abscess is an uncommon and potentially dangerous illness characterized by the buildup of pus in the anatomical area surrounding the spinal column. A 65-year-old female, who has diabetes and high blood pressure, came in with intense discomfort in her lower back that spreads to her lower limbs, making it difficult for her to move. She also has a high fever, excessive sweating, and has lost a large amount of weight. The blood tests indicate the following abnormalities: low Hb level of 9.6 g/dl, low MCV of 70 fl, elevated total white blood cell count of 15.8 × 109/L, elevated neutrophil count of 12.4 × 109/L, normal lymphocyte count of 2.8 × 109/L, high platelet count of 485 × 109/L, and elevated ESR of 110 mm/hr. The level of phosphatase was raised to 247 U/L, which is beyond the usual range of 40-150 U/L. The blood film reveals the presence of hypochromic microcytic red blood cells, which are indicative of iron deficiency anemia. There is also evidence of neutrophil leukocytosis in the white blood cells, with no immature cells observed. Additionally, an increase in platelets is observed in the film. The D-dimer level is 2009 ng/ml, which is within the normal range of less than 500 ng/ml. The CRP level is 48 gm/l, which is above the usual range of less than 6 gm/l. The bone marrow testing yielded normal results. The blood culture indicated the presence of Streptococcus epidermidis growth. Radiological tests revealed that a CE-MRI of the dorsal and lumbar spine indicated the presence of a para-aortic abscess together with septic thrombosis of the inferior vena cava. Paravertebral abscess is a critical emergent condition required a necessary therapy protocols to stabilize the patient status. The timing of intervention is crucial in cases of paravertebral abscess, as the existence of a mass can led to spinal cord compression.

O-arm navigation without apnoea in thoracolumbar and lumbar spine surgery: Outcomes and considerations in a prospective study

BackgroundIntra operative three dimensional navigation-assisted pedicle screw insertion typically requires apnoea for reliable image production. However this carries potential risks to the physiologically compromised patients such as patients having COPD, obesity, cardiac illnesses, and anaemia. In such patients’ safe apnoea time may be as low as 1 min, and can cause life threatening complications. Therefore, this study was done to evaluate the accuracy of thoracolumbar and lumbar pedicle screw insertion using O-arm without using apnoea during imaging, to prevent such possible complications. MethodsThis is a single centre prospective study of 238 patients treated with pedicle screw implantation under O-arm guidance, without using apnoea while imaging. The pedicle breach rate during screw insertion was graded on Gertzbein classification. Also, two senior spine surgeons independently evaluated motion artifacts in the intra operative images and rated them as ‘Significant’ or ‘Non-Significant’ for the procedure. Values of p < 0.05 were considered statistically significant. ResultsDespite not using apnoea in 238 patients with 1120 screws, there were nil screw related complications. Only in one paediatric case of dorsal spine deformity, there were blurred and inaccurate images because of chest expansion, without apnoea. Hence he was given apnoea to render the image reliable for pedicle screw insertion. The screw placement in the pedicles was checked intraoperatively and graded for breach. Grade 2 breach were seen in only 2 cases (n = 3 screws) which were revised intra operatively. The interobserver agreement on motion artifacts was good (κ = 0.565, p < 0.001). ConclusionsThe results of pedicular screw insertion performed without induced apnea are comparable to those achieved with apnea when using O-arm imaging. This technique has proven to be a safe and reliable method for pedicle screw insertion in the thoracolumbar and lumbar spine, potentially mitigating physiological complications. Nonetheless, even minor motion artifacts, on the order of a few millimeters, can significantly impact outcomes in the cervical and upper thoracic spine. Therefore, further research is warranted to evaluate the efficacy and safety of this approach in these regions of the spine.

Two rare localizations of chondrosarcoma: cervical and thoracic spine

Chondrosarcoma is a primary malignant bone tumor, with spinal involvement being rare. Diagnosing this condition can be challenging and typically requires histological verification. Chondrosarcoma has the potential to invade locally and spread systemically. We report the case of 32 year-old women presenting with back pain and weight loss. Magnetic resonance imaging of the spine showed a bone growth at the low cervical spine which extends to the upper dorsal spine. Histological examination showed low-grade chondrosarcoma. Given the tumor proximity to the spinal cord, an incomplete surgical excision was performed followed by radiotherapy sessions. Clinical course was marked by partial regression of the tumor process with a stability of the radiological image of the tumor after a three years follow-up. Our case is original because of the bifocality of the chondrosarcoma in two adjacent segments of the spine.

The Clinical Challenge of Identifying Postural Changes Associated with Musculoskeletal Disorders in a Population of Adolescents: The Evaluation of a Diagnostic Approach.

Background/Objectives: Inappropriate posture, overweight, and physical inactivity are common causes of pathologies on muscles, ligaments, joints, and bone structures, which could negatively impact the quality of present and future life. The challenge of this work was to develop a diagnostic approach to identify the causes of musculoskeletal disorders in an adolescent population in order to implement preventive procedures. Methods: A total of 147 subjects aged between 14 and 18 years who were affected by musculoskeletal disorders and who accessed the Clinical Posturology unit of the IRCCS San Gerardo hospital, Monza, Italy, from 2015 to 2023, were enrolled. The clinical evaluation of each subject included a posturology visit, a physical examination, instrumental devices, such as stabilometric platform, gait analysis, MuscleLab, and imaging tests, such as Radiographic and Magnetic resonance, and a final diagnosis. Results: Ninety-eight (66.6%) subjects reported pain at the lumbar spine (33.3%), followed by knee/lower limb (22.4%), cervical spine (13%), and dorsal spine (12.3%). Imaging diagnostics underlined alterations in the musculoskeletal components, bone dimorphism, and asymmetry of the skeleton in 68% of cases. Thirty-one (21%) subjects received a diagnosis of postural dysfunction, seventy-two (49%) received a diagnosis of somatic dysfunction, and ten (7%) received a diagnosis of both postural and somatic dysfunctions. Conclusions: Our work highlighted that the three instrumental devices used allowed us to detect somatic and postural functional changes that cause musculoskeletal pathologies in adolescents.

Ontogeny and Growth of Early Life Stages of Barred Spiny Eel Macrognathus pancalus (Hamilton, 1822)

Background: The objective of the study was to examine the growth and development of M. pancalus larvae in captive conditions, including pigmentation patterns, yolk and oil globule utilization, growth rates and metamorphosis, as well as to identify suitable live food for larviculture. Methods: The larvae, produced through induced breeding, were kept unfed until the yolk-sac absorption and then fed with freshwater rotifer, mixed zooplankton and Tubifex worms at different stages of development. The larvae were reared in indoor glass tanks and outdoor reinforced plastic tanks to document their morphological and chronological development. Result: The findings showed that the larvae exhibited typical characteristics of eel. Notably, dentition was observed before yolk resorption, indicating the highly predatory nature of the larvae. The bands of melanophores, which were prominent at the beginning, disappeared between 5-7 days post-hatch. Additionally, the study identified distinct features of spiny eels, such as a trunk-like rostral projection at 14 days post-hatch and erectile dorsal spines at 21 days post-hatch. The growth pattern, morphological changes and adaptation to benthic burrowing habits indicated that the larvae metamorphosed into the fry stage between 28-45 days post-hatch. These results provide valuable insights into the ontogenetic development and rearing of M. pancalus and can be used to support future aquaculture and conservation programs.

Characteristics of Morphological Changes in Fins according to Larval Growth of Red Spotted Grouper, Epinephelus akaara.

This study investigated the fin development and morphological characteristics according to larval growth in order to obtain information on behavioral characteristics and optimal stocking density during red seed grouper seed production. To examine the growth and fin development process of the larvae, we randomly sampled at 1, 3, 5, 7, 9, 10, 11, 13, 15, 17, 19, 20, 25, 30, 39, 45, 51, and 72 days after hatching. External morphology was observed and measured using an optical microscope. To observe skeletal development, larvae at 13, 20, 30, and 72 days after hatching were fixed in formalin and stained for cartilage and bone examination. At 9-10 DAH, red spotted grouper larvae (2.74±0.1 to 3.0±0.2 mm TL) exhibited a second dorsal fin spine and pelvic fin spine, which subsequently elongated. At 19-20 DAH, the larvae (5.7±0.1 to 6.1±0.1 mm TL) have the lengths of the second dorsal fin spine and pelvic fin spine average 34% and 31% to total length, respectively. From 30 to 72 DAH (12.6±0.4 to 56.0±0.2 mm TL), the length of the second dorsal fin spine and pelvic fin spine to total length decreased from 27% to 8% for the dorsal fin and 21% to 14% for the pelvic fin, respectively. At 30 DAH (12.6±0.4 mm TL), the larvae reached the complete count of fin rays in each fin. At 39 DAH (20.28±3.07 mm TL), the larvae had fin shapes similar to those of adults. At 13-30 DAH (4.2±0.1 to 12.6±0.9 mm TL), barbs and spinules were distributed along the ridges of the second dorsal and pelvic fin spines. However, at 72 DAH, these barbs and spinules were no longer observed on the fins. During the seed production process, red spotted grouper larvae tend to cluster in the morning, and during this time, entanglement of barbs and spinules on the second dorsal and pelvic fin spines can lead to mortality. Therefore, it is considered essential to focus on managing the behavioral patterns and appropriate rearing density of red spotted grouper larvae from the emergence of barbs and spinules on the second dorsal and pelvic fin spines until they regress and metamorphosis is completed.

Clinical spectrum of demyelinating disease of central nervous system and frequency of anti AQP4 and anti MOG among them: one-year single-center retrospective study

Background: Inflammatory demyelinating diseases of the central nervous system (CNS) are autoimmune conditions leading to significant neurological disability in adults. Recent classifications include myelin oligodendrocyte glycoprotein antibody associated disease (MOGAD) and neuromyelitis optica spectrum disorder (NMOSD) which pose diagnostic challenges due to overlapping clinical and radiological features. This study aimed to assess the clinical spectrum among adults and children diagnosed with CNS demyelinating diseases and to find the proportion of MOG and/or aquaporin-4 (AQP4) autoantibodies amongst them. Methods: This single-center, retrospective study examined 20 patients diagnosed with CNS demyelinating disorders between March, 2023 and February, 2024. Data pertaining to demographics, disease types, CSF analysis, MRI findings, treatment modalities, and serological profiles for anti-AQP4 and anti-MOG antibodies were collected from hospital records and evaluated. Results: Among 20 patients [median age, 34 years (IQR, 18.75); males (n=10) and females (n=10)], acute transverse myelitis (TM) was the most common demyelinating disorder at onset (60%) followed by optic neuritis (ON) (20%). CSF analysis found elevated protein levels in 53% and pleocytosis in 33% of patients. MRI findings revealed longitudinal extensive involvement in 52% of patients, predominantly affecting the cervical and dorsal spine. Serological testing identified 15% positive for anti-AQP4 and 10% for anti-MOG antibodies. MOG+ patients were significantly younger than AQP4+ patients (mean age 16.5 vs. 36.66 years, p=0.016). Both MOG+ patients were male, with 50% presenting with acute TM and 50% with acute disseminated encephalomyelitis. Among AQP4+ patients, the male-to-female ratio was 1:2, with 66.66% presenting with acute TM and 33.33% with ON. Conclusion: CNS demyelinating disorders primarily affect younger individuals, with TM as the most common initial disorder and extensive spinal involvement in cervical and dorsal regions. Serological testing identified three patients with anti-AQP4 and two with anti-MOG antibodies, providing valuable insights into the clinical spectrum of these disorders through cell-based assays.

Glyptothorax pongoensis, a new species of rheophilic catfish (Sisoridae) from the Brahmaputra River drainage, Nagaland, India

ABSTRACT Glyptothorax pongoensis, sp. n. is described from the Yongmon River in Nagaland, India. The new species can be distinguished from its congeners in the Indian subcontinent by the following combination of characters: an ovate-shaped thoracic adhesive apparatus with skin ridges present over the entire apparatus, including the subulate-shaped median depression; presence of plicae on the ventral surface of the pectoral fin spine and the first ray of the pelvic fin; W-shaped anterior nuchal plate element; dorsal-fin origin nearer to the snout tip than to the origin of the adipose fin; posterior margin of dorsal spine rugose with 4–5 ridges, tuberculate skin, and nasal barbel not reaching eye when adpressed. http://www.zoobank.org/urn:lsid:zoobank.org:pub:5D71008D-5D28-4C77-9FA2-D5074DDA7BC9

On the Neotropical Brincadorus: redescription, new species, taxonomic key and description of a related new genus (Insecta: Hemiptera: Cicadellidae: Deltocephalinae)

The Neotropical genus Brincadorus Oman, 1938 is redescribed, and five new species are described and illustrated. Brincadorus cruceno sp. nov., from Bolivia and Peru, can be differentiated by the long and slender aedeagus, with a pre-apical dorsal spine and apex curved downwards. Brincadorus gracilis sp. nov., from Ecuador and Peru, can be distinguished by the slender subgenital plates, aedeagus with slender shaft and basidorsal processes without a preapical tooth. Brincadorus limoncocha sp. nov. from Ecuador, can be differentiated by the robust aedeagus shaft, and bifurcate basidorsal processes. Brincadorus quincemil sp. nov., from Peru, can be distinguished by the bifurcate apex of the subgenital plates, and aedeagus basidorsal process with a preapical dorsal tooth. Brincadorus yanayacu sp. nov., from Ecuador, can be distinguished by the thorn-like apex of the subgenital plates, and short aedeagus, without processes. A key to species is provided, and a female is illustrated and described for the first time. New records for Ecuador and Peru are provided. A new genus that shares similarities with Brincadorus is described. Saltadorus gen. nov. can be distinguished by the smaller size, male pygofer with a pair of long inner lateral processes arising sub-basally on the dorsal region and extending beyond the pygofer apex, widely separated and elongated subgenital plates, and robust aedeagus with a conspicuous sclerotized gonoduct protruding from the atrium. Saltadorus blahniki sp. nov., from Peru, can be identified by the elongated male pygofer, and aedeagus without processes. Saltadorus dietrichi sp. nov., from Peru, can be distinguished by the shorter male pygofer, and aedeagus with a pair of subapical dorsal teeth. Based on the results of recent phylogenomic analyses, Brincadorus is removed from Bahitini and, along with Saltadorus, is considered unplaced to tribe in Deltocephalinae, pending further study.

Genetic mechanisms of axial patterning in Apeltes quadracus

Abstract The genetic mechanisms underlying striking axial patterning changes in wild species are still largely unknown. Previous studies have shown that Apeltes quadracus fish, commonly known as fourspine sticklebacks, have evolved multiple different axial patterns in wild populations. Here, we revisit classic locations in Nova Scotia, Canada, where both high-spined and low-spined morphs are particularly common. Using genetic crosses and quantitative trait locus (QTL) mapping, we examine the genetic architecture of wild differences in several axial patterning traits, including the number and length of prominent dorsal spines, the number of underlying median support bones (pterygiophores), and the number and ratio of abdominal and caudal vertebrae along the anterior–posterior body axis. Our studies identify a highly significant QTL on chromosome 6 that controls a substantial fraction of phenotypic variation in multiple dorsal spine and pterygiophore traits (~15%–30% variance explained). An additional smaller-effect QTL on chromosome 14 contributes to the lengths of both the last dorsal spine and anal spine (~9% variance explained). 1 or no QTL were detected for differences in the numbers of abdominal and caudal vertebrae. The major-effect patterning QTL on chromosome 6 is centered on the HOXDB gene cluster, where sequence changes in a noncoding axial regulatory enhancer have previously been associated with prominent dorsal spine differences in Apeltes. The QTL that have the largest effects on dorsal spine number and length traits map to different chromosomes in Apeltes and Gasterosteus, 2 distantly related stickleback genera. However, in both genera, the major-effect QTL for prominent skeletal changes in wild populations maps to linked clusters of powerful developmental control genes. This study, therefore, bolsters the body of evidence that regulatory changes in developmental gene clusters provide a common genetic mechanism for evolving major morphological changes in natural species.

AB049. Surgery for symptomatic spinal metastases-when, what and how?

Spine is the most common site for metastases in the skeletal system. Longer lifespans of patients with common cancers are translating into increasing incidence of patients with symptomatic spinal metastases. Surgery for spinal metastases offers immediate neurological decompression with stabilization and preservation of quality-of-life parameters. The objectives of the study were to assess the effect of pre-operative neurological condition, timing, and type of surgery on postoperative neurological function and long-term outcome as well as to analyze the various sources of primary in cases of symptomatic spinal metastases and the spinal level involved in terms of postoperative neurological function and ambulation. A retrospective analysis of all operated cases of symptomatic spinal metastases at our institute over a period of 5 years was performed. Parameters such as neurological presentation, timing of surgery, source of primary, and radiological features of the metastases were assessed and compared with the type of surgery performed, post-operative neurological function, and long-term outcome. The in-house hospital information system was to collect data. A total of 94 patients were operated on for symptomatic spinal metastases, the dorsal spine was the most common location and hematological malignancies were the most common primary overall and among men whereas breast was the most common primary in females. Overall, 64.8% of the patients had neurological motor deficits of which 72% had an improvement in motor power. We found that patients with a pre-operative motor power of 3/5 or more likely to have an improvement in post-operative neurological function and ambulatory status. Surgery for symptomatic spinal metastases plays a vital role in preserving the quality of life of the patients. Patients with preoperative motor power of 3/5, spastic tone, and features of mechanical back pain alone have good ambulatory outcomes post-spine surgery.

Molecular phylogeny and taxonomic review of the family Pomacentridae from Korea

A total of eight genera and 21 species of the family Pomacentridae have been reported in Korea, but the classification is uncertain. Therefore, this study aims to clarify molecular phylogeny and classification of eight genera and 17 species of the family Pomacentridae from Korea based on mtDNA sequences (16S rRNA 473 bp), nDNA sequences (RAG1 812 bp) and morphological traits. Molecular phylogenetic trees (ML, and BI) showed that four groups (Chrominae, Glyphisodontinae, Pomacentrinae, and Microspathodontinae) were largely formed, and monophyletic relationship was observed four groups. Each subfamily is divided by the number of spiniform procurrent caudal rays, the shape and rows of the teeth, and the margin of suborbital and preopercle. Each genus is divided by the number of dorsal fin spines and anal fin soft rays, the shape and rows of the teeth, and body coloration. Through an extensive examination of pomacentrids specimens loaned from museum or universities, it is believed that Chromis analis, Neopomacentrus violascens and Pomacentrus chrysurus are not distributed in Korea in spite of their previous records. Finally, we provide key to the species of the family Pomacentridae from Korea.

Postcephalic segmentation and spines of the Siluro-Devonian odontopleurine trilobites Leonaspis Richter &amp; Richter and Kettneraspis Prantl &amp; Přibyl, with description of Bruthansovaspis gen. nov. from the Wenlock to Ludlow of the Prague Basin

Species of the odontopleurine trilobites Leonaspis Richter &amp; Richter, 1917 and Kettneraspis Prantl &amp; Přibyl, 1949 from the Silurian and the Devonian have been studied. Dorsal tubercle and spine patterns are highly variable and deemed of restricted use. The pygidial segmentation of Leonaspis is consistent among species in the development of a rudimentary inner pleural ridge or wide space between the pleural ridge and the axis. In Kettneraspis, an inner pleural ridge is never developed but the primitive condition is to have a space here. The formation of this ridge and an auxiliary interior border spine pair was arrested prematurely during ontogeny in species assigned to Kettneraspis at present. The type species of the monotypic Rupbachella Alberti, 2021 is regarded as a juvenile Leonaspis. Bruthansovaspis gen. nov. (type species: Acidaspis roemeri Barrande, 1852) is proposed for a Silurian clade of former Kettneraspis species from peri-Gondwana, that are principally distinct in lacking the combination of stunted anterior and macropleural posterior, thoracic segments synapomorphic of Kettneraspis and Leonaspis. The types of Bruthansovaspis roemeri, Bruthansovaspis dormitzeri (Hawle &amp; Corda, 1847), Bruthansovaspis dumortieri (Hawle &amp; Corda, 1847), Kettneraspis propinqua (Barrande, 1852), Kettneraspis lindackeri (Hawle &amp; Corda, 1847) and Bruthansovaspis zenkeri (Hawle &amp; Corda, 1847) (= B. dormitzeri) from the Silurian of the Barrandian, all of which had previously been lumped as dormitzeri, are figured and their classifications revisited. Exceptionally well-preserved odontopleurine material from the Devonian in the Tafilalt (southern Morocco) is described as Kettneraspis freitagi sp. nov. Leonaspis? strix Lütke, 1965 from the Devonian of the Harz Mountains is in need of revision; a previously tentatively assigned pygidium does not belong in that genus.