Differential Mitochondrial Adaptation of the Slow and Fast Skeletal Muscles by Endurance Running Exercise in Streptozotocin-Induced Diabetic Mice.

The skeletal muscle is the main organ responsible for insulin action, and glucose disposal and metabolism. Endurance and/or resistance training raises the number of mitochondria in diabetic muscles. The details of these adaptations, including mitochondrial adaptations of the slow and fast muscles in diabetes, are unclear. This study aimed to determine whether exercise training in streptozotocin (STZ)-induced mice leads to differential adaptations in the slow and fast muscles, and improving glucose clearance. Eight-week-old mice were randomly distributed into normal control (CON), diabetes (DM), and diabetes and exercise (DM+Ex) groups. In the DM and DM+Ex groups, mice received a freshly prepared STZ (100 mg/kg) intraperitoneal injection on two consecutive days. Two weeks after the injection, the mice in the groups ran on a treadmill for 60 min at 20 m/min for a week and subsequently at 25 m/min for 5 weeks (5 days/week). The analyses indicated that running training at low speed (25 m/min) enhanced mitochondrial enzyme activity and expression of lactate and glucose transporters in the plantaris (low-oxidative) muscle that improved whole-body glucose metabolism in STZ-induced diabetic mice. There were no differences in glucose transporter expression levels in the soleus (high-oxidative) muscle. The endurance running exercise at 20-25 m/min was sufficient to induce mitochondrial adaptation in the low-oxidative muscles, but not in the high-oxidative muscles, of diabetic mice. In conclusion, the present study indicated that running training at 25 m/min improved glucose metabolism by increasing the mitochondrial enzyme activity and glucose transporter 4 and monocarboxylate transporter 4 protein contents in the low-oxidative muscles in STZ-induced diabetic mice.

Whole-body cryotherapy enhances the expression of heat shock protein 70 and related hormones.

BACKGROUND: Whole-body cryotherapy (WBC) is used as a conditioning method for athletes. However, the scientific evidence for its effects is still insufficient. OBJECTIVE: To elucidate the effects of transient WBC on the expression of heat shock protein (HSP) 70 and the secretion of related hormones in humans. MATERIALS AND METHODS: The participants in this study were six healthy adult men. WBC was performed for 3 min in a booth at a temperature in the range of -150 to -120 degree C, and measurements were taken immediately before (Pre), immediately after (Post), and 60 min after WBC (Post60). For measurement of core body temperature (gastrointestinal temperature), participants ingested a capsule-type wireless temperature sensor. The body surface temperature was measured using a noncontact thermometer, and measurements were taken at four sites on the body surface (chest, abdomen, front of the thigh, and front of the lower thigh). Leukocyte count, lactate dehydrogenase, creatine kinase, hemoglobin, hematocrit, adrenaline, noradrenaline, cortisol, adrenocorticotropic hormone (ACTH), erythropoietin, and HSP70 in the collected blood were measured. RESULTS: The results showed a decrease in body surface temperature and an increase in noradrenaline and ACTH immediately after WBC. In addition, the core body temperature decreased 60 min after WBC, accompanied by an increase in HSP70 expression. CONCLUSION: WBC may increase HSP70 expression via noradrenaline and ACTH. The results of this study suggest the usefulness of WBC in triggering protein synthesis and the maintenance of immune function after training. doi.org/10.54680/fr22210110512.

Intravoxel Incoherent Motion in Normal Pituitary Gland: Initial Study with Turbo Spin-Echo Diffusion-Weighted Imaging.

BACKGROUND AND PURPOSE: DWI with conventional single-shot EPI of the pituitary gland is hampered by strong susceptibility artifacts. Our purpose was to evaluate the feasibility of intravoxel incoherent motion assessment by using DWI based on TSE of the normal anterior pituitary lobe. MATERIALS AND METHODS: The intravoxel incoherent motion parameters, including the true diffusion coefficient (D), the perfusion fraction (f), and the pseudo-diffusion coefficient (D*), were obtained with TSE-DWI in 5 brain regions (the pons, the WM and GM of the vermis, and the genu and splenium of the corpus callosum) in 8 healthy volunteers, and their agreement with those obtained with EPI-DWI was evaluated by using the intraclass correlation coefficient. The 3 intravoxel incoherent motion parameters in the anterior pituitary lobe were compared with those in the brain regions by using the Dunnett test. RESULTS: The agreement between TSE-DWI and EPI-DWI was moderate (intraclass correlation coefficient = 0.571) for D, substantial (0.699) for f', but fair (0.405) for D*. D in the anterior pituitary lobe was significantly higher than in the 5 brain regions (P < .001). The f in the anterior pituitary lobe was significantly higher than in the 5 brain regions (P < .001), except for the vermian GM. The pituitary D* was not significantly different from that in the 5 brain regions. CONCLUSIONS: Our results demonstrated the feasibility of intravoxel incoherent motion assessment of the normal anterior pituitary lobe by using TSE-DWI. High D and f values in the anterior pituitary lobe were thought to reflect its microstructural and perfusion characteristics.

Effects of collagen hydrolysate on the tibialis anterior muscle and femur in senescence-accelerated mouse prone 6.

OBJECTIVES: Effects of collagen hydrolysate (CHD) on the oxidative capacity of the tibialis anterior muscle and the cortical and trabecular density of the femur were investigated in senescence-accelerated mouse prone 6 (SAMP6). METHODS: Sixteen-week-old male SAMP6 mice were divided into control (CON) and CHD groups. The CON group was given normal water, while the CHD group was given water containing CHD. Fibre cross-sectional areas (CSAs), fibre succinate dehydrogenase (SDH) staining intensity, and SDH activity of the tibialis anterior muscle were determined at 42 and 60 weeks of age. The cortical and trabecular density of the femur and serum osteocalcin levels were also determined. RESULTS: The fibre SDH staining intensity and muscle SDH activity were higher in the CHD group at 60 weeks of age than in the age-matched CON group. The cortical and trabecular density and serum osteocalcin levels were greater in the CHD group at 60 weeks of age than in the age-matched CON group. CONCLUSION: CHD inhibited th age-induced decrease in muscle oxidative capacity and bone density of SAMP6 mice. There is a possibility that CHD is effective for inhibition of age-induced degeneration in the musculoskeletal system.

A Randomized Clinical Trial Evaluating rh-FGF-2/ß-TCP in Periodontal Defects.

Biological mediators have been used to enhance periodontal regeneration. The aim of this prospective randomized controlled study was to evaluate the safety and effectiveness of 3 doses of fibroblast growth factor 2 (FGF-2) when combined with a ß-tricalcium phosphate (ß-TCP) scaffold carrier placed in vertical infrabony periodontal defects in adult patients. In this double-blinded, dose-verification, externally monitored clinical study, 88 patients who required surgical intervention to treat a qualifying infrabony periodontal defect were randomized to 1 of 4 treatment groups-ß-TCP alone (control) and 0.1% recombinant human FGF-2 (rh-FGF-2), 0.3% rh-FGF-2, and 0.4% rh-FGF-2 with ß-TCP-following scaling and root planing of the tooth prior to a surgical appointment. Flap surgery was performed with EDTA conditioning of the root prior to device implantation. There were no statistically significant differences in patient demographics and baseline characteristics among the 4 treatment groups. When a composite outcome of gain in clinical attachment of 1.5 mm was used with a linear bone growth of 2.5 mm, a dose response pattern detected a plateau in the 0.3% and 0.4% rh-FGF-2/ß-TCP groups with significant improvements over control and 0.1% rh-FGF-2/ß-TCP groups. The success rate at 6 mo was 71% in the 2 higher-concentration groups, as compared with 45% in the control and lowest treatment groups. Percentage bone fill in the 2 higher-concentration groups was 75% and 71%, compared with 63% and 61% in the control and lowest treatment group. No increases in specific antibody to rh-FGF-2 were detected, and no serious adverse events related to the products were reported. The results from this multicenter trial demonstrated that the treatment of infrabony vertical periodontal defects can be enhanced with the addition of rh-FGF-2/ß-TCP (ClinicalTrials.gov NCT01728844).

Decreased D2-40 immunoreactivity in stored paraffin sections and methods for preserving it.

D2-40, a monoclonal antibody against podoplanin, is a selective marker of lymphatic endothelium and is widely used for research on and diagnosis of pathology of lymphatic vessels. We examined the relation between the duration of tissue section storage and changes in immunostaining by D2-40 antibody; we evaluated also the effects of preservation methods on changes in immunostaining during storage. Staining by D2-40 was attenuated by long-term preservation of scalp skin and lymph node sections at room temperature. The attenuation of D2-40 staining in stored sections was improved by preservation at low temperature, i.e., 4° or - 30° C. We investigated also the immunostaining of preserved tissue sections using NZ-1 and Lyve-1, which are antibodies against lymphatic endothelium markers. Staining by NZ-1 or Lyve-1 antibody was detected clearly in sections that had been stored for 16 weeks. Our study suggests that either long-term storage of D2-40 immunostained tissue sections should be avoided or the section should be preserved at low temperature.

Does dopamine block the spawning of the acroporid coral Acropora tenuis?

Most corals undergo spawning after a particular moon phase, but how moon-related spawning is endogenously regulated in corals remains unknown. The objective of the present study was to evaluate whether dopamine (DA) affects spawning in Acropora tenuis. When pieces of four A. tenuis colonies were reared under a natural photoperiod and water temperature, spawning was observed after the predicted moon phase. After exposure to water containing DA at 0.1 µM, pieces of the same colonies only released 5 to 10 bundles. Co-treatment with DA and pimozide (D1 and D2 receptors antagonist), but not domperidone (D2 receptor antagonist), induced mass release of bundles from the colonies. A cross-experiment revealed high fertilization rates between the control colonies (95%) and between the control and DA-treated colonies (90%), suggesting that gametes developed normally in coral tissue. Therefore, DA appears to have an inhibitory effect on the spawning of A. tenuis.

Which factors increase procedural thromboembolic events in patients with unruptured paraclinoid internal carotid artery aneurysm treated by coil embolization?

We analyzed the factors which increase the frequency of procedural thromboembolic events during coil embolization of unruptured paraclinoid internal carotid artery aneurysms. Neurologically symptomatic complications did not occur in our series. Silent hyperintense lesions on postoperative DWI were frequently detected after the coiling procedure in which we needed to withdraw the unreleased coil. Patient's age, sex, aneurysm diameter, packing density, use of balloon-assisted technique, and exchanging maneuver of microcatheter during the procedure did not increase the frequency of silent thromboembolic events.

Preliminary results on the reproduction of a deep-sea snailfish Careproctus rhodomelas around the active hydrothermal vent on the Hatoma Knoll, Okinawa, Japan.

Deep-sea snailfish Careproctus rhodomelas were collected from an active hydrothermal vent using a remotely operated vehicle (R.O.V. Hyper-dolphin) and a pressurized device (Deep-Aquarium). Careproctus rhodomelas exhibited a cystovarian-type ovary containing a small number of developing oocytes at different stages, suggesting that the fish is a batch-spawner that spawns large eggs (c. 6·0 mm) several times within its life span. In vitro culture of the oocytes in the presence of human chorionic gonadotropin showed that oestradiol-17ß production fluctuated with oocyte development, suggesting that the oocytes were at the vitellogenic stage.

External and internal controls of lunar-related reproductive rhythms in fishes.

Reproductive activities of many fish species are, to some extent, entrained to cues from the moon. During the spawning season, synchronous spawning is repeated at intervals of c. 1 month (lunar spawning cycle) and 2 weeks (semi-lunar spawning cycle) or daily according to tidal changes (tidal spawning cycle). In species showing lunar-related spawning cycles, oocytes in the ovary develop towards and mature around a specific moon phase for lunar spawners, around spring tides for semi-lunar spawners and at daytime high tides for tidal spawners. The production of sex steroid hormones also changes in accordance with synchronous oocyte development. Since the production of the steroid hormones with lunar-related reproductive periodicity is regulated by gonadotropins, it is considered that the higher parts of the hypothalamus-pituitary-gonad axis play important roles in the perception and regulation of lunar-related periodicity. It is likely that fishes perceive cues from the moon by sensory organs; however, it is still unknown how lunar cues are transduced as an endogenous rhythm exerting lunar-related spawning rhythmicity. Recent research has revealed that melatonin fluctuated according to the brightness at night, magnetic fields and the tidal cycle. In addition, cyclic changes in hydrostatic pressure had an effect on monoamine contents in the brain. These factors may be indirectly related to the exertion of lunar-related periodicity. Molecular approaches have revealed that mRNA expressions of light-sensitive clock genes change with moonlight, suggesting that brightness at night plays a role in phase-shifting or resetting of biological clocks. Some species may have evolved biological clocks in relation to lunar cycles, although it is still not known how lunar periodicities are endogenously regulated in fishes. This review demonstrates that lunar-related periodicity is utilized and incorporated by ecological and physiological mechanisms governing the reproductive success of fishes.

[The utility of coronary magnetic resonance angiography in children under six years of age with Kawasaki disease].

BACKGROUND: To follow up coronary arterial lesions due to Kawasaki disease (KD) using noninvasive magnetic resonance coronary angiography (MRCA), we studied a method to improve the quality of images in young children. METHOD: Non-contrast enhanced, free-breathing MRCA with the vector ECG gating real-time navigator-echo 3D steady-state free precession (SSFP) technique was performed using a 1.5-T whole-body MR imaging system (Philips) in 68 children with KD aged 4 months to less than 6 years. A flex medium coil was used. Data were acquired with a 180 to 200 mm field of view (FOV) and were reconstructed with a 512 x 360 matrix. Patients were sedated during the examination. Many parameters were optimized for each patient; i.e., FOV, acquisition delay, turbo-field echo-factor, navigator-window and resolution, which resulted in the acquisition of high-resolution and high-signal images of the coronary arteries. RESULTS: These conditions remarkably improved not only the quality of the images, but also the detection rate of coronary arterial segments (American Heart Association) in the children. The rates were as follows; Segments 1 (97%), 2 (97%), 3 (87%), 4 (66%), 5 (97%), 6 (96%), 7 (83%), 8 (56%), 9 (53%), 10 (21%), 11 (96%), 12 (29%), 13 (93%), 14 (54%), and 15 (65%). CONCLUSION: MRCA is a useful method for evaluation coronary aneurysms from the early stages of KD, even in infants and small children.

Improvement of temporal and dynamic subtraction images on abdominal CT using 3D global image matching and nonlinear image warping techniques.

Accurate registration of the corresponding non-enhanced and arterial-phase CT images is necessary to create temporal and dynamic subtraction images for the enhancement of subtle abnormalities. However, respiratory movement causes misregistration at the periphery of the liver. To reduce these misregistration errors, we developed a temporal and dynamic subtraction technique to enhance small HCC by 3D global matching and nonlinear image warping techniques. The study population consisted of 21 patients with HCC. Using the 3D global matching and nonlinear image warping technique, we registered current and previous arterial-phase CT images or current non-enhanced and arterial-phase CT images obtained in the same position. The temporal subtraction image was obtained by subtracting the previous arterial-phase CT image from the warped current arterial-phase CT image. The dynamic subtraction image was obtained by the subtraction of the current non-enhanced CT image from the warped current arterial-phase CT image. The percentage of fair or superior temporal subtraction images increased from 52.4% to 95.2% using the new technique, while on the dynamic subtraction images, the percentage increased from 66.6% to 95.2%. The new subtraction technique may facilitate the diagnosis of subtle HCC based on the superior ability of these subtraction images to show nodular and/or ring enhancement.

The morphology and ultrastructure of the peripheral olfactory organ in newly metamorphosed coral-dwelling gobies, Paragobiodon xanthosomus Bleeker (Gobiidae, Teleostei).

We examined the peripheral olfactory organ in newly metamorphosed coral-dwelling gobies, Paragobiodon xanthosomus (SL=5.8mm+/-0.8mm, N=15), by the aid of electron microscopy (scanning and transmission) and light microscopy. Two bilateral olfactory placodes were present in each fish. They were oval-shaped and located medio-ventrally, one in each of the olfactory chambers. Each placode had a continuous cover of cilia. The placode epithelium contained three different types of olfactory receptor neurons: ciliated, microvillous and crypt cells. The latter type was rare. Following a pelagic larval phase, P. xanthosomus settle to the reef and form an obligate association with one species of coral, Seriatopora hystrix. Their well-developed olfactory organs likely enable larvae of P. xanthosomus to detect chemical cues that assist in navigating towards and selecting appropriate coral habitat at settlement. Our findings support past studies showing that the peripheral olfactory organ develops early in coral reef fishes.

MR Imaging of Hippocampal Sulcus Remnant: Age-Related Differences.

The hippocampal sulcus remnant (HSR) is often observed at the medial temporal lobe on MR images. In the present study, we made a retrospective assessment of the frequency and age-related differences in HSR in routine brain MR examinations of 1000 patients, 494 females and 506 males. Cases with one or several spots that were hypointense on T1-weighted and FLAIR images and hyperintense on T2-weighted images were defined as positive for HSR. Abnormal spots with the same intensity as cerebrospinal fluid were observed in 210 out of 506 males and in 193 out of 494 females. No significant sex-related differences were observed in the frequency of HSR. The HSR was seen more frequently with age in both males and females. Patients with hypertension had a significantly higher frequency of HSR.

Analysis of proteinaceous components of the organic matrix of endoskeletal sclerites from the alcyonarian Lobophytum crassum.

The mesoglea of alcyonarians is occupied by an abundance of minute calcitic sclerites. The sclerites of the alcyonarian Lobophytum crassum contain a water-soluble organic matrix comprising 0.48% of the sclerite weight and a water-insoluble fraction comprising 1.15% of the sclerite weight. Analysis of proteinaceous components in the soluble fraction shows a particularly high content of aspartic acid, followed by alanine, glycine, and glutamate. Aspartic acid, glycine, alanine, and glutamate are the most abundant residues in the insoluble fraction. In both cases, the fractions show the highest concentration of aspartic acid from the total proteins. In an in vitro assay, we show that the matrix proteins extracted from the calcitic sclerites induce the formation of amorphous calcium carbonate prior to its transformation into the calcitic crystalline form. We also show scanning electron micrographs of the rhombohedral calcite crystals used as template, the protein imprinted with these crystals. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of both matrices shows the protein fractions at 67 and 48 kDa. The soluble matrix shows two additional faint bands. Both fractions stain for a carbohydrate at 67 kDa, indicating a glycoprotein at this molecular weight. A newly derived protein sequence was subjected to bioinformatics analysis involving identification of similarities to other acidic proteins. The identification of these proteins in alcyonarian endoskeletal sclerites emphasizes the fundamental importance of such acidic proteins and sheds more light on the functions of these proteins in the processes of biocalcification.

Morphological Change of Unruptured Vertebral Artery Dissection on Serial MR Examinations. Evaluation of the Arterial Outer Contour by Basi-parallel Anatomical Scanning (BPAS)-MRI.

SUMMARY: Basi-parallel anatomical scanning (BPAS)- MRI is a simple MRI technique to reveal the surface contour of the intracranial vertebrobasilar artery. The purpose of this study was to investigate the usefulness of BPAS-MRI for observing the temporal course of unruptured vertebral artery (VA) dissection in patients by means of serial MR examinations. Since April 2003, we performed serial MR examinations in four patients with unruptured acute vertebral artery dissection. The frequency of the MR examinations during the follow-up period in each patient varied from twice within seven months to five times within 19 months. Both MRA and BPAS-MRI were obtained in each MR examination. We investigated the course of morphological changes within the dissected artery on BPASMRI (outer contour) and on MRA (inner lumen). Although the initial MRA showed fusiform dilatation, irregular stenosis or normal caliber at the dissected lesion, the initial BPAS-MRI disclosed fusiform dilatation in all of the four patients. In two patients, MRA finding of the VA lesion had changed, though the fusiform appearance had been stationary on BPAS-MRI. Then both dissolution of the fusiform dilatation on BPAS-MRI and normalization of the inner luminal caliber on MRA were confirmed within nine months. In one patient, fusiform dilatation on both BPAS-MRI and MRA resolved simultaneously on the MR examination at eight months after the initial symptom. In another patient, fusiform dilatation of the outer contour was still enlarging on BPAS-MRI ten months after the onset, though the fusiform dilatation on MRA had been stationary since the eighth week. We performed endovascular coil embolization in this patient eleven months after the initial symptom. Resolution of the fusiform dilatation on BPAS-MRI should be a healing sign of VA dissection. Persisting the fusiform dilatation or progressively enlarging outer contour on BPASMRI may be an unstable sign. BPAS-MRI provides more information about the instability of the dissected lesion. We should obtain not only MRA but also BPAS-MRI for the course observation of unruptured VA dissection.

Rescue use of endovascular snare for acute basilar artery embolic occlusion resistant to balloon angioplasty and fibrinolysis therapy.

A rescue clot disruption using a basket snare is described for acute basilar artery embolic occlusion resistant to balloon angioplasty and fibrinolysis therapy. In spite of failed balloon angioplasty in conjunction with fibrinolysis, a basket-shaped snare connected to a microguide wire could be used to catch and crush the clot in the upper basilar artery. The rescue use of a snare may be effective for angioplasty-resistant acute embolic stroke.

Differential susceptibility to oxidative stress of two scleractinian corals: antioxidant functioning of mycosporine-glycine.

This study examined the importance of mycosporine-glycine (Myc-Gly) as a functional antioxidant in the thermal-stress susceptibility of two scleractinian corals, Platygyra ryukyuensis and Stylophora pistillata. Photochemical efficiency of PSII (F(v)/F(m)), activity of antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), and composition and abundance of mycosporine-like amino acids (MAAs) in the coral tissue and in symbiotic zooxanthellae were analyzed during 12-h exposure to high temperature (33 degrees C). After 6- and 12-h exposures at 33 degrees C, S. pistillata showed a significantly more pronounced decline in F(v)/F(m) compared to P. ryukyuensis. A 6-h exposure at 33 degrees C induced a significant increase in the activities of SOD and CAT in both host and zooxanthellae components of S. pistillata while in P. ryukyuensis a significant increase was observed only in the CAT activity of zooxanthellae. After 12-h exposure, the SOD activity of P. ryukyuensis was unaffected in the coral tissue but slightly increased in zooxanthellae, whereas the CAT activity in the coral tissue showed a 2.5-fold increase. The total activity of antioxidant enzymes was significantly higher in S. pistillata than in P. ryukyuensis, suggesting that P. ryukyuensis is less sensitive to oxidative stress than S. pistillata. This differential susceptibility of the corals is consistent with a 20-fold higher initial concentration of Myc-Gly in P. ryukyuensis compared to S. pistillata. In the coral tissue and zooxanthellae of both species investigated, the first 6 h of exposure to thermal stress induced a pronounced reduction in the abundance of Myc-Gly but not in other MAAs. When exposure was prolonged to 12 h, the Myc-Gly pool continued to decrease in P. ryukyuensis and was completely depleted in S. pistillata. The delay in the onset of oxidative stress in P. ryukyuensis and the dramatic increase in the activities of the antioxidant enzymes in S. pistillata, which contains low concentrations of Myc-Gly suggest that Myc-Gly provides rapid protection against oxidative stress before the antioxidant enzymes are induced. These findings strongly suggest that Myc-Gly is functioning as a biological antioxidant in the coral tissue and zooxanthellae and demonstrate its importance in the survival of reef-building corals under thermal stress.

Successful staged treatment for ruptured blister-like dissecting aneurysm of the intracranial internal carotid artery: acute GDC embolization for the blister-like aneurysm followed by proximal occlusion with extracranial-intracranial bypass in the chronic stage.

The surgical treatment of ruptured blister-like dissecting aneurysm on the internal carotid artery (ICA) is still controversial. We report a case of this disease successfully managed by a staged treatment: GDC packing into the blister-like aneurysm in the acute stage followed by proximal occlusion in the chronic stage. The merit of this staged treatment is to prevent rerupture in the acute stage and to allow the proximal occlusion in the chronic stage with or without an extracranial-intracranial bypass, after assessment of tolerance of the ICA occlusion.

Spermatozoal ultrastructures of two marine perciform teleost fishes, the goatfish, Paraupeneus spilurus (Mullidae) and the rabbitfish, Siganus fuscescens (Siganidae) from Taiwan.

Mature spermatozoa of two perciform teleost fishes, Paraupeneus spilurus (Mullidae) and Siganus fuscescens (Siganidae) from Taiwan were examined using transmission and scanning electron microscopy. Despite the fact that spermatozoa of both species are of the primitive type, the results of the present study highlight the potential application of spermatozoal morphology in studies of fish phylogenetic relationships. To our knowledge, the flattened nucleus observed in P. spilurus spermatozoa is reported for the first time. Several features common to Sigandae spermatozoa-the unusual almost parallel situation of the centrioles, the arrangement of mitochondria and the near absence of shallow nuclear fossa-are significantly different from other common teleost sperm types. These unique features may be synapomorphies for the Siganidae and Mullidae and evidently contribute to the study of phylogenetic relationships in teleosts.