Sperm phylogeny of Characidae (Teleostei, Characiformes)

The phylogeny of the very diverse Neotropical fish family Characidae has been the subject of several recent contributions based on morphological characters, molecular data or both in combined analyses. In cases of conflict between these kinds of data, resolution by combined analyses most often tends to agree with the molecular evidence, given the disproportionate number of characters it contains in comparison with morphological datasets. This happens especially after the advent of massive DNA sequencing methods. In this contribution, we present the most comprehensive set of characters from sperm and spermiogenesis of the Characidae. Since these traits are not expected to be functionally correlated with the general morphology or molecular markers, we consider them a third source of data. We provide a phylogenetic analysis from a combined dataset of seven molecular markers (6444 characters), general morphology (520 characters) and reproductive features (94 characters) coded for 165 species of characiform fishes. Parsimony analyses were done under extended implied weighting under 30 different combinations of weighting schemes and strengths. Most parsimonious trees from two different weighting conditions were selected as representative samples of the obtained topologies, in order to evaluate the performance of the reproductive characters. One of these hypotheses is more conservative regarding the currently accepted phylogenies and the other is the most parsimonious tree that we found as the best correlated with the morphological data. Reproductive characters are shown to be more homoplastic than general morphology and DNA, but provided synapomorphies for 23–24 nodes that had no morphological synapomorphies, justifying their use in phylogenetic analyses. Also, in combination with data from general morphology and considering details of the phylogenetic analysis, they showed to have the potential to challenge well-established hypotheses based on molecular data.Fil: Mirande, Juan Marcos. Fundación Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Baicere Silva, Clarianna M.. Universidade Do Estado de Mato Grosso (unemat);Fil: Santana, Júlio C. O.. Universidade do Brasília; BrasilFil: Quagio Grassiotto, Irani. Universidade Estadual Paulista Julio de Mesquita Filho; Brasi

Gephyrocharax machadoi, a new species of Stevardiinae (Characiformes: Characidae) from the Rio Paraguai basin, central Brazil

Ferreira, Katiane M., Faria, Érika De, Ribeiro, Alexandre C., Santana, Júlio C. O., Quagio-Grassioto, Irani, Menezes, Naércio A. (2018): Gephyrocharax machadoi, a new species of Stevardiinae (Characiformes: Characidae) from the Rio Paraguai basin, central Brazil. Zootaxa 4415 (1): 161-172, DOI: https://doi.org/10.11646/zootaxa.4415.1.

An assessment approach for application of spermatic data in phylogenetic analyses: Within the genus Moenkhausia Eigenmann, 1903 (Characiformes: Characidae)

Spermiogenesis and sperm ultrastructure from 21 species of Moenkhausia and others related genera are described. To evaluate the phylogenetic signals, 18 unordered characters were utilized in implied weighting analysis through the program TNT 1.1. Four variations of spermiogenesis were found. In the earliest spermatids, the nucleus can be positioned lateral, eccentric, strongly eccentric or nearly medial in relation to the distal centriole. The nuclear rotation can be present or absent. These spermiogenesis processes are related or intermediate to Type I and Type III. Taking into account the degrees of nuclear rotation during the spermiogenesis and other characteristics, distinct forms of spermatozoa are observed among the species analyzed. The phylogenetic analysis yielded a single most parsimonious tree with fit value 2.70000 and the topology obtained founds Moenkhausia as non-monophyletic. However, some hypothesis of relationships previously proposed viz the clade 20, which contains the type species Moenkhausia xinguensis, is recovered herein. This clade is supported by five synapomorphies, and it allows the supposition that these species constitute a monophyletic group. The whole topology is presented and discussed. © 2012 The Authors. Acta Zoologica © 2012 The Royal Swedish Academy of Sciences

Gephyrocharax machadoi Ferreira & Faria & Ribeiro & Santana & Quagio-Grassioto & Menezes 2018, new species

<i>Gephyrocharax machadoi</i>, new species <p>Fig. 1</p> <p> <i>Gephyrocharax</i> sp. Lima & Ribeiro, 2011: 152 (occurrence in the rio Paraguai basin; based on MZUSP 90000).</p> <p> <b>Holotype</b>. CPUFMT 2429 (37.6 mm SL, male), Brazil, Mato Grosso, Tangará da Serra, Rio Sepotuba (14°30’05”S, 57°34’39”W), W.P. Troy, 15 October 2010.</p> <p> <b>Paratypes.</b> All from Brazil, Mato Grosso: CPUFMT 2428, 6, 33.9–39.3 mm SL; MZUSP 123130, 1, 36.8 mm SL, collected with holotype; CPUFMT 1463, 2, 40.9–41.4 mm SL, 1 c&s, 42.2 mm SL, Nova Marilândia, Rio Sepotuba (14°25’29”S 57°11’06”W), G.M.M. Figueiredo, 19 March 2011; CPUFMT 1464, 3, 25.7–26.5 mm SL, Tangará da Serra, Rio Ararão (14°30’23”S 57°34’00”W), G.M.M. Figueiredo, 21 March 2011; CPUFMT 2387, 5, 29.1–36.6 mm SL, Tangará da Serra, Rio Sepotuba (14°30’06”S 57°34’39”W), W. Troy, November 2011; MZUSP 90000, 2, 17.5–31.5 mm SL, Tangará da Serra, Rio Sepotuba (14°30'04"S, 57°34'38"W), H.A. Britski, O. Froehlich & F. Marques, 10 March 2002.</p> <p> <b>Diagnosis.</b> <i>Gephyrocharax machadoi</i> differs from all congeners, except <i>Gephyrocharax major</i>, by presenting two modified scales on the ventral caudal-fin lobe: a larger, sexually dimorphic scale, slightly superior and anterior in position, followed by a smaller, posterior and ventrally placed accessory scale (vs. a single modified pouch scale without ventrally placed accessory scales). <i>Gephyrocharax machadoi</i> differs from <i>G</i>. <i>major</i> by presenting a gap (more conspicuous in mature males than in mature females) (see sexual dimorphism below) between the second and third ventral procurrent caudal-fin rays (vs. second and third ventral procurrent caudal-fin rays near each other or fused distally); premaxilla with tricuspid teeth (vs. tetra- to pentacuspid teeth); and body depth 21.5–25.4% of the SL (vs. 25.9–36.8% in SL).</p> <p> <b>Description.</b> Morphometric and meristic data of holotype and paratypes presented in Table 1. Body laterally compressed, moderately elongate, largest specimen 41.4 mm SL. Greatest body depth situated at dorsal-fin origin. Dorsal profile of head slightly convex from margin of upper lip to tip of supraoccipital spine; straight from tip of supraoccipital spine to dorsal-fin origin; straight along dorsal-fin base; straight from posterior terminus of dorsalfin base to adipose-fin insertion, and slightly concave from latter point to caudal-fin origin. Ventral profile of body convex from tip of lower jaw to anal-fin insertion, slightly concave along anal-fin base and slightly concave ventral to caudal peduncle.</p> <p>Dorsal-fin rays ii, 8* (17). Length of first unbranched dorsal-fin ray less than one-half length of second unbranched ray. Dorsal-fin origin located posterior to vertical crossing the origin of the anal-fin origin. Dorsal-fin first pterygiophore inserted behind sixteenth neural spine of caudal vertebra. Adipose fin present. Pectoral-fin rays i, 11* (17). Pelvic fin rays i,5,i* (17), longest ray not reaching anal-fin origin. Anal fin with three unbranched rays followed by 30* (8), 31 (7) or 32 (2) branched rays. Caudal-fin forked; lobes similar in size. Principal caudal-fin rays i,17,i* (17).</p> <p>Scales cycloid. Lateral line complete, with 46 (2), 47* (4), 48 (5), 49 (3), 51 (1) or 52 (2) perforated scales. Six (17)* longitudinal rows of scales between dorsal-fin origin and lateral line, five (17)* between lateral line and pelvic-fin origin. Predorsal scales in an irregular series of 26 (1), 27 (3), 28 (3), 29* (6), 30 (2) or 31 (2).</p> <p>Circumpeduncular scales (17). Single row of five to seven scales extending along anal-fin base. Basal portion of both caudal-fin lobes covered by medium-sized scales, about same size as those present on caudal peduncle (see Sexual Dimorphism section for more details).</p> <p>Mouth superior, lower jaw projecting slightly anterior to tip of upper jaw. Premaxilla with two rows of teeth (Fig. 2). Outer tooth row aligned in gentle arch, with 3 (7) or 4* (10) tricuspid teeth. Inner premaxillary tooth row with 5 (8) or 6* (9) tricuspid teeth; both outer and inner tooth rows with median cusps largest. Maxilla with 1 (1), 2 (12) or 3* (3) large tricuspid teeth with median cusps slightly more developed. Dentary with five large anterior teeth with three cusps, with median cusps largest, followed by smaller conic teeth.</p> <p>First gill arch with 12 (5) gill rakers on hypobranchial and ceratobranchial, 6 (5) rakers on epibranchial, and 1 (5) on cartilage between ceratobranchial and epibranchial.</p> <p> <b>Color in alcohol.</b> Males and females with approximately the same color pattern. Overall ground coloration yellowish tan. Head and body of specimens retaining guanine on scales, therefore somewhat silvery. Dorsal surface of head and lips with dense concentration of dark chromatophores. Scattered dark chromatophores covering 1/3 of opercular region, upper and lower lips, nostrils and on maxilla, lateral ethmoid, frontal, parietal and occipital process. Dark chromatophores concentrated on predorsal scales. Concentration of chromatophores decreasing progressively from middorsal region to lateral line, where limited to edges of scales. Chromatophores in scales of abdominal region below lateral line. Few chromatophores present between lateral line and anal fin. Humeral blotch vertically elongate on fourth and fifth perforated lateral line scale, extending two or three scale rows above and one scale row below lateral line. Midlateral stripe on body extending from humeral blotch to caudal peduncle, located above lateral line. Large dark blotch on caudal peduncle. Dorsal, pectoral, pelvic, and caudal fins hyaline, with scattered dark chromatophores outlining rays and forming straight lines. Dark chromatophores concentrated along distal borders of interradial membranes of anal-fin base. Adipose fin pale, with small, dark chromatophores concentrated on posterior base of fin.</p> <p> <b>Distribution.</b> <i>Gephyrocharax machadoi</i> is known only from tributaries of the rio Sepotuba, upper rio Paraguai Basin, Mato Grosso, Brazil (Fig. 3).</p> <p> <b>Etymology.</b> <i>Gephyrocharax machadoi</i> is named in honor of the Brazilian ichthyologist Francisco de Arruda Machado, Universidade Federal de Mato Grosso, for his great contribution in the conservation of neotropical freshwater fishes, especially in the Mato Grosso state.</p> <p> <b>Sexual dimorphism.</b> Sexually mature males with two modified scales on the caudal-fin ventral lobe. First modified scales larger, more anterior and superior in position (slightly below lateral line), triangular in shape and covering almost the entire portion of the caudal-fin ventral lobe (Fig. 4A). Females also present a modified scale, with size and position similar to the modified scale abovementioned, however, this scale present a rounded margin (Fig. 4B). The second modified caudal-fin scale in males is smaller, more posterior and inferior in position, and cover the posterior half of procurrent caudal-fin rays 1, 2 and 3.</p> <p>Both sexually mature males and females present a gap between ventral procurrent caudal-fin rays 2 and 3. This gap is more developed in sexually matures males than in females (Fig. 5).</p> <p>Sexually mature males have bony hooks on rays of pelvic, anal, and caudal fins. All branched pelvic-fin rays have small, slender, anterolaterally oriented hooks along nearly entire length of each ray, usually one hook per segment. Anal-fin bony hooks very small and located on the largest unbranched ray up to the sixth branched ray; usually, there are nine hooks per ray. Caudal fin with three or four small, slender, anterodorsally oriented hooks, on the branched portions of the fourth to sixth rays.</p> <p> <b>Histological analysis.</b> <i>Gephyrocharax machadoi</i> has spermatozoa with ovoid nuclei, and packs of spermatozoa were observed inside the female’s ovary (Fig. 6).</p> <p> <b>Spermiogenesis description.</b> In early spermatids the nucleus is spherical and displays granular chromatin homogenously distributed (Fig. 7A–B). The centriolar complex and the flagellum lie laterally to the nucleus and it is anchored to the plasma membrane (Fig. 7A–C). The proximal centriole is anterior and oblique in relation to distal centriole (Fig. 7C). The distal centriole differentiates into basal body that organizes the axoneme of the forming flagellum (Fig. 7C–D). The centriolar complex migrates towards the nucleus. The nucleus moves up to the centriolar complex (Fig. 7B–C), where a depression, the nuclear fossa, is formed in nuclear outline at the centriolar complex point (Fig. 7C). The organelles are dispersed around the nucleus at opposite area to the centriolar complex (Fig. 7D–E). The chromatin gradually starts a synchronous condensation process (Fig. 7A–E). The nucleus rotates towards the forming flagellum and assumes an eccentric position (Fig. 7D–E). Also, the cytoplasm shifts towards the flagellum, giving rise to the midpiece (Fig. 7A–E). The distal centriole is anchored to the plasma membrane, and the cytoplasm encircles the initial portion of the flagellum forming the cytoplasmic canal (Fig. 7B). The midpiece is irregular and contains the mitochondria and vesicles (Fig. 7A, E). The axoneme of the flagellum is formed by the classical microtubule disposition 9+2 (not shown).</p> <p> <b>Spermatozoon description.</b> The nucleus displays granular chromatin (Fig. 8A–I), is elongated in direction of the flagellum and drop-shaped in cross section (Fig. 8A–B). The nucleus is split into an anterior larger and a posterior smaller, which involves the initial portion of the flagellum (Fig. 8C–E). The nuclear outline has a double concavity located in a superolateral position in relation to the nucleus, the nuclear fossa (Fig. 8F). The proximal centriole is partially inside the nuclear fossa and the distal centriole is totally outside it (Fig. 8F). Within the centriolar complex, the proximal centriole has an oblique position forming an acute angle in relation to the distal centriole (Fig. 8F). The midpiece is irregular and contains mitochondria and vesicles (Fig. 8A–B). The mitochondria are elongated and irregular-shaped, without branches, and distributed through the midpiece and the nuclear periphery (Fig. 8A–B, G–I). Two mitochondria are found in the spermatozoon (I–J). A cytoplasmic projection without organelles, called citoplasmatic sleeve, is found at the end of the midpiece (Fig. 8L). Only one flagellum is present (Fig. 8A–B, D) with the classical pattern of the axoneme (9 + 2, 9 pairs of peripheral microtubules and 2 central microtubules) (Fig. 8I).</p>Published as part of <i>Ferreira, Katiane M., Faria, Érika De, Ribeiro, Alexandre C., Santana, Júlio C. O., Quagio-Grassioto, Irani & Menezes, Naércio A., 2018, Gephyrocharax machadoi, a new species of Stevardiinae (Characiformes: Characidae) from the Rio Paraguai basin, central Brazil, pp. 161-172 in Zootaxa 4415 (1)</i> on pages 162-168, DOI: 10.11646/zootaxa.4415.1.8, <a href="http://zenodo.org/record/1241898">http://zenodo.org/record/1241898</a&gt

Testing the phylogenetic hypotheses of Stevardiinae Gill, 1858 in light of new phenotypic data (Teleostei: Characidae)

The Stevardiinae are a high diverse subfamily of Characidae, the richest family of Neotropical fishes. Many species are inseminating (internal fertilization) and consequently display diverse morphology of reproductive organs and sperm cells. We test the monophyly and internal relationships of the Stevardiinae through a phylogenetic analysis based on a new set of morphological characters, including reproductive traits, combined with publicly available molecular data. We defined 176 characters from general morphology and primary and secondary sexual characters, coded for 54 species. Analyses were made under parsimony using a broad range of extended implied weighting parameters. Given the different morphological characters we use, this analysis provides additional synapomorphies and an independent test for previous hypotheses based on morphological and combined morphological and molecular datasets. Our final hypothesis is a single most parsimonious tree of 6341 steps obtained under three different weighting schemes. This recovers the monophyly of the tribes Creagrutini, Diapomini, Glandulocaudini, Hemibryconini, Landonini (including Eretmobryconini), Stevardiini, and Xenurobryconini. It also supports the recognition of the monotypic tribe Phenacobryconini. Insemination is ambiguously optimized as present in the common ancestor of Stevardiinae and in the common ancestor of all members of the subfamily except for Landonini. That reconstruction constitutes a novel hypothesis about the evolution of insemination within Characidae.Fil: Ferreira, Katiane M.. Universidade Federal de Mato Grosso; BrasilFil: Mirande, Juan Marcos. Fundación Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Quagio Grassiotto, Irani. Universidade Estadual Paulista "júlio de Mesquita Filho"; BrasilFil: Santana, Júlio C. O.. Universidade Federal do Mato Grosso do Sul; BrasilFil: Baicere Silva, Clarianna Martins. Universidade Federal de Mato Grosso; BrasilFil: Menezes, Naércio A.. Universidade de Sao Paulo; Brasi

Relationship of post-weaning growth and age at puberty in crossbred beef heifers

This study was intended to evaluate body size structure and growth parameters of crossbred heifers fed at four nutritional levels to achieve puberty earlier. Animals were classified depending on their level of crossing between Nelore and Hereford and subjected to four nutritional levels (kg day–1) as follows: 0.5 (light; n = 32), 0.75 (medium; n = 32), 1.00 (high; n = 29), and 1.25 (very high; n = 27). Heifers at puberty and at weaning were individually classified for growth parameters. The fat thickness and longissimus muscle area throughout the experimental period were determined by ultrasonography. The height, heart girth, frame, and weight:height ratio were variables used to evaluate body traits. Univariate analysis of variance using the GLIM MIXED procedure os SPSS was performed and the significance level was set at 0.05. Age and body weight at puberty were 388±1.9 days and 331.4±1.3 kg, respectively. Body condition score demonstrated an interaction between nutritional level and crossbred degree. Heifers with the highest degree of Nelore had higher fat thickness and lower weight:height ratio compared with other racial groups at puberty. Pearson correlation coefficient showed a negative association for body condition score (–0.34) and fat thickness (–0.58) compared with age at puberty. The increased fat thickness at younger ages at puberty was observed in all racial groups. The increased weight:height ratio at younger ages at puberty was observed in all racial groups. We observed higher values for a frame in animals at the higher level of supplementation. There is a greater correlation between live weight gain and phenotypic traits during weaning to achieve puberty at an earlier age in crossbred heifers