Midpiece Width Research Articles

CARACTERIZACIÓN MORFOMÉTRICA Y CLASIFICACIÓN DE LOS ESPERMATOZOIDES DE VICUÑA (Vicugna vicugna) USANDO EL SISTEMA ISAS® CASA-Morph

The aim of the study was to determine the morphological and morphometric characteristics of the vicuña sperm (Vicugna vicugna), looking for possible subpopulations in its structure. Semen was collected by electroejaculation method from three adult male vicuñas weighing 50.33 ± 2.52 kg, once per animal. The volume, color and concentration, sperm morphology and morphometry were determined. The samples for the analysis of sperm morphology and morphometry were stained with Hemacolor®, and analyzed using the CASA-Morph, Integrated Semen Analysis System (ISAS®v1). Five forms of the vicuña sperm head were distinguished: normal, piriform, long, short and rounded. The morphometric parameters determined were the length, width, area, perimeter, ellipticity, elongation, regularity and rugosity of the vicuña sperm head, percentage of acrosome, head gray level, as well as the width, area, distance and angle of insertion of midpiece of the sperm. In relation to morphology, significant differences (P <0.05) were found in the percentage distribution of head shapes, with the normal shape (55.7%) being the majority and different from the other shapes. Significant differences (P <0.05) were found between animals in the morphometric variables of head, percentage of acrosome, ellipticity, rugosity, elongation and gray level; while the variables of the midpiece and regularity did not show differences (P> 0.05). The morphometric variables were distributed in four main components (PCA) called elongation, area, circularity and midpiece width, which explained 84.59% of the total variance. The cluster analysis determined five subpopulations (SP): SP1 grouped small cells of low length, width and area (18.8%); SP2 of sperm of large size, both in area and width of the head (17.38%); SP3 of rounded cells with high values of percentage of acrosome and head gray level (24.04%); SP4 of spermatozoa of intermediate size and elongated, with greater ellipticities and elongation (23.61%); and SP5 of cells of intermediate size and short, with low values of area and length (16.71%).

PSX-A-21 Late-Breaking: Predicting live weight using linear body measurements in growing dairy calves

Abstract The objective of this study was to explore how linear body measurements are related to body weight and can be used to predict calf body weight using linear and machine learning models. To meet these objectives, a total of 69 Holstein calves from a commercial dairy farm were enrolled in the study from wk 2 – 8 of age. Calves were weighed and linear measurements were collected weekly. Nineteen linear measurements were obtained each week, including: poll to nose, width across the eyes, width across the right ear, neck length (NL), wither height (WH), heart girth (HG), midpiece height (MH), midpiece circumference (MC), midpiece width (MW), midpiece depth (MD), midpiece width across the 13th rib (MW13), hook height, hook width, pin height, top of pin bones width (PW), nose to tail body length, the length between the withers and pins (WPL), forearm to hoof, cannon bone to hoof. These measurements were taken using a commercial soft tape measure and calipers. Using a machine learning approach, models were generated to predict BW from calf linear measurements using Weka software 3.8.5 (University of Waikato, New Zealand) using a 10-fold cross-validation method. Both linear regression (LR) and random forest (RF) models were evaluated. Across all weeks the LR model derived 12 of the 19 traits to fit the BW model (r2 = 0.93). These included: PN, NL, WH, HG, MC, MW, MD, HW, PW, MW13, WPL. The RF model slightly reduced BW predictions (r2= 0.92). The results of this study suggest that linear models built on linear measurements can accurately estimate body weight in dairy calves. These data and models generated are important to further the development of visualized weighing systems for young dairy calves and may be used to accurately predict BW without a scale.

PSIII-5 Predicting live weight using linear body measurements in growing beef calves

Abstract The objective of this study is to investigate how linear body measurements relate to and can be used to predict calf body weight using linear and machine learning models. To meet these objectives, a total of 103 Angus cross calves were enrolled in the study from wk 2 - 8. Calves were weighed and linear measurements were collected weekly, such as: poll to nose, width across the eyes (WE), width across the right ear, neck length, wither height, heart girth (HG), midpiece height (MH), midpiece circumference, midpiece width (MW), midpiece depth (MD), hook height, hook width, pin height, top of pin bones width (PW), width across the ends of pin bones, nose to tail body length, the length between the withers and pins, forearm to hoof, cannon bone to hoof. These measurements were taken using a commercial soft tape measure and calipers. To assess relationships between traits and to fit a model to predict BW, data were analyzed using the Weka (The University of Waikato, New Zealand) software using both linear regression (LR) and random forest (RF) machine learning models. The models were trained using a 10-fold cross-validation approach. The automatically derived LR model used 11 traits to fit the data to weekly BW (r2 = 0.97), where the traits with the highest coefficients were HG, PW and WE. The RF model improved further the BW predictions (r2= 0.98). Additionally, sex differences were examined. Although the BW model continued to fit well (r2 0.97), some of the top linear traits differed. The results of this study suggest that linear models built on linear measurements can accurately estimate body weight in beef calves, and that machine learning can further improve the model fit.

Ultrastructural characteristics of black marsh turtle spermatozoa obtained by electroejaculation.

The black marsh turtle (Geoemydidae: Siebenrockiella crassicollis) is a freshwater turtle that occurs in equatorial tropical climates in South East Asia. The semen of S. crassicollis was investigated by electroejaculation. The spermatozoa of S. crassicollis are filiform in shape with curved heads. The entire length, midpiece to tail length, tail width and tail length of the spermatozoa were 71.33±1.55μm, 49.92±1.13μm, 0.43±0.02μm and 48.53±0.25μm, respectively. The head length, head width across the middle and head width across the base were 14.00±0.38μm, 0.79±0.03μm and 0.91 ±0.0.03μm, respectively. The acrosomal region of the S. crassicollis spermatozoa was narrower than the head, with an acrosomal length and width at the annulus of 2.90±0.13μm and 0.43±0.01μm, respectively. The midpiece of the S. crassicollis spermatozoa was narrower than the head and contained 30-40 mitochondrial balls, each with a ball diameter of 0.16±0.002μm. The midpiece length, midpiece width and tail length were 4.92±0.16, 0.78±0.03 and 48.53±0.25μm, respectively. This study presents the characteristic appearance of a freshwater turtle spermatozoa in Southeast Asia, as observed under an electron microscope. The spermatozoa of Siebenrockiella crassicollis are morphologically different from those of other freshwater turtles from other regions described in previous studies.

Sperm Morphology in Neotropical Primates.

Simple SummaryThe spermatozoon is a highly differentiated cell, whose morphology has been affected throughout evolution by selective forces such as the competition between the sperm of rival males (sperm competition) and the joint evolution of male and female reproductive tracts (coevolution). The study of its morphology is important when analyzing the relationships between different species. In this contribution we analyzed new specimens and produced a database with all the spermatozoa dimensions recorded to date, comprising 75 individuals from 20 species and 8 genera, representing 2 families of neotropical primates (Cebidae and Atelidae). After an evolutionary analysis, we observed two different trends for the Cebidae and Atelidae families. Narrower and shorter spermatozoa seem to be the ancestral (oldest) form for Cebidae, with an evolutionary trend toward spermatozoa with wider and larger heads in the derived (younger) species. In Atelidae, on the contrary, narrower heads are observed in the more derived groups. We analyzed these results in the context of sperm competition and mating systems in these groups. More studies are needed to improve our knowledge of the evolution of the spermatozoa in neotropical primates.The morphological and morphometric characterization of spermatozoa has been used as a taxonomic and phylogenetic tool for different species of mammals. We evaluated and compared the sperm morphometry of five neotropical primate species: Alouatta caraya, Ateles belzebuth and Ateles chamek of family Atelidae; and Cebus cay (=Sapajus cay) and Cebus nigritus (=Sapajus nigritus) of family Cebidae. After the collection of semen samples, the following parameters were measured on 100 spermatozoa from each specimen: Head Length, Head Width, Acrosome Length, Midpiece Length, Midpiece Width and Tail Length. Considering the available literature on sperm morphometry, we gathered data of 75 individuals, from 20 species, 8 genera and 2 families. These data were superimposed on a phylogeny to infer the possible direction of evolutionary changes. Narrower and shorter spermatozoa seem to be the ancestral form for Cebidae, with a trend toward wider and larger heads in derived groups. The spermatozoa of Atelidae may show an increase in total length and midpiece length. Sperm heads would have become narrower in the more derived groups of Ateles. Sperm length may increase in the more derived species in both families. Our results are discussed in the context of sperm competition and sexual selection.

Qualitative ultrastructural changes and morphometry of deccani sheep spermatozoa preserved with egg yolk citrate extender

The present investigation was aimed to study the sequential changes in the sperm cell deterioration dur-ing liquid storage of Deccani sheep breed semen from dilution to 48 h of storage along with its seminal characteris-tics and sperm morphometric measurement. Thus the two Deccani adult rams (aged 2 years), were selected (six ejaculates/each ram) and the collected semen was diluted with Egg yolk citrate extender (EYC) (final concentration - 400 million spermatozoa/0.2 ml semen).Seminal characteristics were assessed along with sperm morphologi-cal changes by Electron microscopy immediately after dilution, at 24 and 48 h of storage, respectively. Sperm morphometry was analysed by Image analysis.The percentage of Individual motility, Live spermatozoa, Acrosomal integrity and Hos-test reactive sperm decreased significantly (P<0.05) from 80.41 to 49.16%, 82.75 to 51.25%, 94.16 to 83% and 76 to 48.58%, respectively during liquid storage of semen from initial dilution to 48 h of storage. The sperm head length (?m), Head width, sperm head area (?m2), sperm head perimeter (?m), mid piece length (?m), proximal mid piece width (?m), distal midpiece width (?m), volume of mid piece (?m3) and acrosomal cap length (?m) were 7.80, 4.33, 26.84, 20.63, 14.03, 0.74, 0.51, 4.54 and 5.24, respectively. Electron microscopic qualitative evaluation revealed that the main site of injury is the apical ridge of ram spermatozoa when stored at 5ºC. The electron density of the mitochondria reduced indicating concomittant depletion of ATP and loss of motility resulting in reduction of fertility.

The effects of inbreeding on sperm morphometry of captive-bred endangered mammals

Captive breeding is used for the conservation of endangered species, but inbreeding can result when a small number of founders are used to establish populations. Inbreeding can reduce the proportion of normal sperm in an ejaculate, but may also have effects on sperm size and shape (morphometry). We investigated the effects of inbreeding on sperm morphometry of black-footed ferrets (Mustela nigripes (Audubon and Bachman, 1851)) and red wolves (Canis rufus Audubon and Bachman, 1851) from captive breeding programs to determine if more inbred males produced sperm of poor quality (bulky head, small midpiece, short tail). We measured sperm head length, head width, midpiece length, midpiece width, and tail length on 10 sperm from each male of both species. A negative relationship between variation in sperm tail length and inbreeding coefficient (f) was found in black-footed ferret, suggesting that more inbred individuals will have reduced genetic and phenotypic variation. Analyses indicated a negative relationship between sperm head width and f and a positive relationship between sperm tail length and f in red wolf, suggesting that more inbred male red wolves could have faster sperm. These results indicate that inbreeding affects functionally important aspects of sperm morphometry, but that these effects may not be entirely negative.

Interferometric phase microscopy for label-free morphological evaluation of sperm cells

To compare label-free interferometric phase microscopy (IPM) to label-free and label-based bright-field microscopy (BFM) in evaluating sperm cell morphology. This comparison helps in evaluating the potential of IPM for clinical sperm analysis without staining. Comparison of imaging modalities. University laboratory. Sperm samples were obtained from healthy sperm donors. We evaluated 350 sperm cells, using portable IPM and BFM, according to World Health Organization (WHO) criteria. The parameters evaluated were length and width of the sperm head and midpiece; size and width of the acrosome; head, midpiece, and tail configuration; and general normality of the cell. Continuous variables were compared using the Student's t test. Categorical variables were compared with the χ(2) test of independence. Sensitivity and specificity of IPM and label-free BFM were calculated and compared with label-based BFM. No statistical differences were found between IPM and label-based BFM in the WHO criteria. In contrast, IPM measurements of head and midpiece width and acrosome area were different from those of label-free BFM. Sensitivity and specificity of IPM were higher than those of label-free BFM for the WHO criteria. Label-free IPM can identify sperm cell abnormalities, with an excellent correlation with label-based BFM, and with higher accuracy compared with label-free BFM. Further prospective clinical trials are required to enable IPM as part of clinical sperm selection procedures.

Sperms biometry of local Iraqi Awassi Rams

This study was designed to estimate of sperms biometry in local Iraqi Awassi rams. Five mature rams of 2.5-4 years old and 37-44 Kg live body weight were used in this study. Semen collection was performed by using an artificial vagina. Semen samples were evaluated immediately after collection of total 30 ejaculates. Semen volume and color, mass and individual sperms motility, live and abnormal sperms, as well as sperms concentration, were estimated. sperms biometry calculated by using phase contrast microscope and occulo-micrometer lens. Semen biometry means which estimated in this study were; sperms head length 9.62± 1.2 microns, sperms head width 5.32± 2.5 microns, acrosome length 6.10 ± 2.4 microns, head base width 2.54 ± 1.8 microns, midpiece length 11.92 ± 3.6, midpiece width 2.21 ± 0.8 microns, tail length 50. 62 ± 2.1 microns.

Sperm characteristics in plains (Bison bison bison) versus wood (Bison bison athabascae) bison

The objective was to compare sperm characteristics between the two subspecies of North American bison, plains bison (Bison bison bison) and wood bison (Bison bison athabascae). Frozen-thawed ejaculated sperm from age-matched plains (n = 3) and wood (n = 2) bison were evaluated for morphometry, motility, viability, protein profile, and in vitro fertilization characteristics. Sperm morphometry and motility were assessed with computer-based systems, viability was assessed with SYBR-14 and propidium iodide, and fertilizing ability was determined using a heterologous in vitro fertilization system (using bovine oocytes). For plains versus wood bison, there were significant differences for head width (4.76 ± 0.22 vs 4.71 ± 0.19 μm; mean ± SD), head area (35.64 ± 1.91 vs 34.72 ± 2.64 μm2), head perimeter (23.61 ± 0.68 vs 23.31 ± 0.98 μm), midpiece length (14.58 ± 0.4 vs 14.36 ± 0.51 μm), midpiece width (0.81 ± 0.06 vs 0.79 ± 0.07 μm), and tail length (46.61 ± 2.15 vs 45.98 ± 2.08 μm). However, there was no significant difference in head length (overall, 9.04 ± 0.37 μm), progressive motility (41.16 ± 8.39%), or viability (41.58 ± 5.58%). Based on two-dimensional gel electrophoresis, 93 out of 113 protein spots were similar in their expression patterns. Furthermore, we inferred that differences in sperm biometry between these subspecies did not affect in vitro fertilization percentage (overall, 82.62 ± 12.13%). Based on these findings, we concluded that plains bison were an appropriate research model for developing reproductive technologies for wood bison.

Morphology, chemical contents and physiology of chondrostean fish sperm: a comparative study between Siberian sturgeon (Acipenser baerii) and sterlet (Acipenser ruthenus)

Summary The present study was carried out with two sturgeon species, Siberian sturgeon (Acipenser baerii) and sterlet (A. ruthenus) to compare spermatological parameters to better understand inter-species differences. Significant differences between morphometric features were observed such as acrosome length, acrosome width, head length, midpiece width and flagellar length, while midpiece length did not reveal such differences. The sterlet has a shorter spermatozoon than the Siberian sturgeon. Ultrastructural parameters vary significantly in terms of length of the nucleus, diameter of the endonuclear canals (EC), size of posterolateral projections (PP) and diameter of flagellum. Mean values for density of spermatozoa in the semen, seminal plasma pH, osmolality (mOsmol kg−1), along with Ca2+, Na+, K+, Cl− ions concentrations (mm) were determined to be 0.61 ± 0.37 × 109, 8.16 ± 0.18, 77.20 ± 52.28, 0.24 ± 0.06, 31.39 ± 10.21, 3.51 ± 1.10, 14.00 ± 4.30 in A. baerii and 0.41 ± 0.32 × 109, 8.13 ± 0.19, 50.74 ± 6.27, 0.16 ± 0.11, 20.11 ± 3.78, 1.26 ± 0.54, 6.11 ± 0.60 in A. ruthenus, respectively. Significant differences were observed in Na+, K+ and Cl− concentrations in the seminal plasma as well as in sperm velocity. The percentage of motile spermatozoa did not show any significant difference between the two species. Comparing the results of this study with published literature data on sturgeon spermatozoa reveals that morphological and ultrastructural parameters of spermatozoa together with some parameters of the seminal fluid and spermatozoa velocity can be used in comparative spermatology to better understand inter-species differences. The observed biochemical and physiological differences should be also considered for the development of methods for controlled reproduction and for sperm cryopreservation techniques.

Spermatozoal morphologies and fructose and citric acid concentrations in agouti ( Dasyprocta leporina) semen

This study was conducted to identify the levels of fructose and citric acid, and sperm morphologies in agouti ( Dasyprocta leporina) semen. These parameters may be important in identifying highly fertile semen from the agouti. The objectives were: (1) to investigate spermatozoal abnormalities in agouti semen and (2) to determine the concentrations of seminal fructose and citric acid in agouti semen samples. Semen samples were collected from 16 anaesthetised male agouti by electro-ejaculation. Fructose and citric acid concentrations were 256.86 ± 63.54 mg/dl and 1877 ± 147 mg/dl, respectively, measured with ELISA kits. Sperm morphologies, examined using eosin-negrosin staining, showed 11 morphologies. The most abundant (68.5%) sperm morphology (M1) showed no known sperm defects. Means for head, mid piece, tail and total length of the agouti spermatozoa was 5.23 ± 0.04 μm, 5.18 ± 0.08 μm, 37.52 ± 0.24 μm and 47.96 ± 0.25 μm, respectively for M1 sperm. The means of spermatozoa head and mid piece width and semen volume were 3.26 ± 0.04 μm, 0.70 ± 0.02 μm and 0.47 ± 0.16 ml, respectively. It was concluded that as the fructose concentration in agouti ejaculate increased the percentage of spermatozoa with known spermatozoa defects increased ( r = 0.506; P < 0.037; n = 32). It is suggested that the M1 sperm could be the most competitive spermatozoa in agouti ejaculate. In conclusion standards for identifying fertile agouti semen were established.

Identification of sperm morphometric subpopulations in the canine ejaculate: do they reflect different subpopulations in sperm chromatin integrity?

A statistical approach using sequentially principal component analysis (PCA) clustering and discriminant analysis was developed to disclose morphometric sperm subpopulations. In addition, we used a similar approach to disclose subpopulations of spermatozoa with different degrees of DNA fragmentation. It is widely accepted that sperm morphology is a strong indicator of semen quality and since the sperm head mainly comprises the sperm DNA, it has been proposed that subtle changes in sperm head morphology may be related to abnormal DNA content. Semen from four mongrel dogs (five replicates per dog) were used to investigate DNA quality by means of the sperm chromatin structure assay (SCSA), and for computerized sperm morphometry (ASMA). Each sperm head was measured for nine primary parameters: head area (A), head perimeter (P), head length (L), head width (W), acrosome area (%), midpiece width (w), midpiece area (a), distance (d) between the major axes of the head and midpiece, angle (theta) of divergence of the midpiece from the head axis; and four parameters of head shape: FUN1 (L/W), FUN2 (4pi A/P2), FUN3 ((L - W)/(L + W)) and FUN 4 (pi LW/4A). The data matrix consisted of 2361 observations, (morphometric analysis on individual spermatozoa) and 63,815 observations for the DNA integrity. The PCA analysis revealed five variables with Eigen values over 1, representing more than 79% of the cumulative variance. The morphometric data revealed five sperm subpopulations, while the DNA data gave six subpopulations of spermatozoa with different DNA integrity. Significant differences were found in the percentage of spermatozoa falling in each cluster among dogs (p < 0.05). Linear regression models including sperm head shape factors 2, 3 and 4 predicted the amount of denatured DNA within each individual spermatozoon (p < 0.001). We conclude that the ASMA analysis can be considered a powerful tool to improve the spermiogram.

Do Computer‐Assisted, Morphometric‐Derived Sperm Characteristics Reflect DNA Status in Canine Spermatozoa?

It is widely accepted that sperm morphology is a strong indicator of semen quality. As the sperm head mainly comprises the sperm DNA, it is have been proposed that subtle changes in sperm morphology may be related to abnormal DNA content. Semen from four mongrel dogs was used to investigate DNA quality by means of the sperm chromatin structure assay (SCSA), and for computerized sperm morphometry (CASMA). Each sperm head was measured for nine primary parameters [head area (A), head perimeter (P), head length (L), head width (W), midpiece width (w), midpiece area (a), distance (d) between the major axes of the head and midpiece, angle (theta) of divergence of the midpiece from the head axis] and four parameters of head shape [FUN1, L/W; FUN2, 4piA/P(2); FUN3, (L - W)/(L + W); FUN4, piLW/4A]. Significant differences were found in all CASMA-derived parameters among dogs (p < 0.001). Linear regression models including sperm head shape factors 1, 3 and 4 predicted the extent of DNA denaturation (p < 0.001). We conclude that the CASMA analysis can be considered a powerful tool to improve the spermiogram.

Use of the Sperm-Class Analyser for objective assessment of human sperm morphology.

The Sperm-Class Analyser was validated for assessing morphometric parameters of the head and midpiece of unwashed and washed human ejaculated spermatozoa from volunteers providing a wide range of semen quality. A higher proportion of sperm could be assessed (86% fresh semen and 75% washed sperm) if Hemacolor staining was used rather than DiffQuik (80 and 73%) or Papanicolaou (78 and 68%). Different stains employed different fixatives and the area, length, width and perimeter of the sperm head was significantly larger for washed sperm stained by Hemacolor and DiffQuik. Acrosomal area ranged from 48 to 51% of the sperm head area and this percentage was larger for washed sperm stained with DiffQuik. Sperm at the end of the slide, distant from the initial semen droplet, were larger in area and perimeter than those at that site or in the middle. The high precision and reproducibility of the equipment required assessing only 50 sperm on the slide. Far greater variation was found in head width, relative acrosomal area and midpiece width between different slides prepared from the same ejaculate, highlighting the inherent variability within the ejaculate and smear preparation, and requiring more than one slide to be assessed.

Use of computerized image analysis in the morphometric characterization of giant panda (Ailuropoda melanoleuca) spermatozoa obtained from the epididymis 4 hours postmortem

AbstractThe reproductive tract of Chu‐Lin, a giant panda that had died at Madrid Zoo, was removed. Four hours postmortem the epididymides was cut with a blade, and the spermatozoa were collected and immersed in a freezing medium. The sample was kept under refrigeration at 5°C. After 4 hr the sperm suspension was aspirated into 0.25‐mL straws, which were held for 7 min in nitrogen vapors before they were plunged into liquid nitrogen. To characterize sperm population and distribution, a morphometric study of the triple‐stained smears of the thawed semen sample was undertaken with the aid of computerized image analysis. Spermatozoa with intact acrosomes were selected and assessed using an immersion lens (1,000×) and bright‐field illumination. The software made it possible to take six basic linear measurements of each spermatozoon: maximum head width (HW), base of the head (BH), maximum head length (HL), midpiece length (ML), midpiece width (MW), and terminal piece length (TL). The system was connected to a data base from which derived parameters could be calculated: head form factor (HL/HW), total flagellum length (TFL), total sperm length (TSL), and the proportion of each of the sections in relation to the whole. The results of the morphometric study did not demonstrate the existence of sperm subpopulations, as the measurements of the 100 spermatozoa analyzed were relatively homogeneous with regard to their distribution for each of the parameters considered. The sperm head of the giant panda displayed a relatively rounded morphology, and the HL/HW was 1.24±0.03. Mean head length was 5.05±0.08 µ, and mean head width was 4.07±0.08 µ. The mean total length of the giant panda spermatozoon was 49.26±0.67 µ. Zoo Biol 22:355–364, 2003. © 2003 Wiley‐Liss, Inc.

Spermiometrics: objective and reproducible methods for evaluating sperm morphology.

An approach was made to replace the subjective evaluation of human sperm morphology by an objective method applicable in routine laboratories. 20 patients out of infertile marriages (G2 and G3) were compared with 10 normal, fertile men (G1). Two different methods were used. Highly developed instruments and techniques were used in method 1, and cheap and simple ones, designed for routine laboratories, in method 2. Head area, circumference, length, and maximal midpiece width of 100 spermatozoa/subject were determined by a semi-automatic image analysis system. Head variation and average midpiece width were clearly bigger in G2 and G3 than in G1. As a result, formulae were developed, determining the pathological alteration of sperm head and midpiece for the individual semen. In addition, an objective classification into different sperm types was elaborated. Using the developed formulae, results of methods 1 and 2 are well in agreement. Thus, method 2 is recommended for routine laboratories, allowing an objective and reproducible morphology determination within 30 min.

Spermatozoal Morphology and Ultrastructure of Channel Catfish, Ictalurus punctatus

Abstract The morphology, dimensions, aberrations, and ultrastructure of channel catfish (Ictalurus punctatus) spermatozoa were studied. Spermatozoa of a wild catfish stock from Louisiana were compared to those of a domestic stock from Mississippi. The spermatozoon of channel catfish consists of a rounded dark head, a collar-dike midpiece, and a long flagellum. The average dimensions were: head length, 2.3 μm; midpiece length, 1.6 μm; midpiece width, 3.1 μm; and flagellum length, 94.9 μm. The flagellum had the classical (2.9 + 2) axoneme. On the average, 4.7% of the spermatozoa in the fish studied were biflagellar. Each flagellum arose from an individual centriolar complex. Domestic fish stock had a higher percentage of normal gametes compared to wild stock.