Cichlasoma Cyanoguttatum Research Articles

Rio Grande Cichlid Established in the Lake Pontchartrain Drainage, Louisiana

Rio Grande Cichlid Established in the Lake Pontchartrain Drainage, Louisiana

Observations on the biology of Rhabdochona kidderi texensis, a parasite of North American cichlids.

An examination of a sample of benthic invertebrates collected from the Upper San Marcos River in southwestern Texas, USA in September 1999 revealed that the nymph of the ephemeropteran Tricorythodes curvatus served as natural intermediate host of the nematode Rhabdochona kidderi texensis (Nematoda: Rhabdochonidae), an intestinal parasite mainly of the Rio Grande perch (Cichlasoma cyanoguttatum) in this locality; the prevalence of the parasite's third- and fourth-stage larvae in mayflies was 6.8% with the intensity of 1-2 larvae per nymph. Live R. kidderi texensis eggs collected from nematodes recovered from C. cyanoguttatum in Texas were transported to the Czech Republic, where they were used to experimentally infect nymphs of the palaearctic mayfly species Paraleptophlebia submarginata; the development of infective third- and fourth-stage larvae in this experimental intermediate host was completed after approximately 10 days at 19 degrees C. Infected nymphs were fed to aquarium-reared fishes, four Cichlasoma nigrofasciatum and one Oreochromis niloticus, of which only three of the former became infected. The last (fourth) moult of a male nematode was observed in C. nigrofasciatum 23 days p.i. and adult males and gravid females with not fully mature (non-embryonated) eggs in uteri on days 40 and 51 p.i. The prepatent period of R. kidderi texensis is approximately two months.

The First Record of Fish as Paratenic Hosts of Falcaustra spp. (Nematoda: Kathlaniidae)

Two types of third-stage nematode larvae (most of which were encapsulated) were collected from the abdominal cavity and liver of the freshwater fishes Etheostoma fonticola, Etheostoma lepidotum, Cichlasoma cyanoguttatum, Lepomis auritus, Lepomis sp., and Gambusia affinis in Texas and are referred to the genus Falcaustra. This is the first record of Falcaustra larvae from fishes, and their presence may reflect the importance of fishes as paratenic hosts of turtle parasites in this genus.

The fishes of northern and central Veracruz, Mexico

The northern and central part of Veracruz, Mexico, as herein delimited, is inhabited by 121 species of fish, in 83 genera and 47 families. Four species and 3 families are Nearctic, 28 species and 6 families are Neotropical, and 1 species is circumtropical. Ecologically, 8 species and 4 families are primary, 25 species and 6 families are secondary, 30 families are peripheral, and 7 families are marine, many of them marine accidentals. A mountainous area near Punta del Morro almost reaches the sea, and acts as a filter for primary and secondary species. Its importance had not been described in detail. From the north, the following species range to Punta del Morro or less:astyanax mexicanus, Dionda ipni, Ictalurus cf.furcatus, I. cf.punctatus, Lucania parva, Cyprinodon variegatus, Gambusia affinis, G. vittata, Heterandria sp.,Poecilia formosa, P. latipinna, Xiphophorus birchmani, X. variatus, Cichlasoma cyanoguttatum, C. labridens andC. sp.. From the south, the species that approach or reach Punta del Morro are:Astyanax aeneus, Hyphessobrycon compressus, Rhamdia guatemalensis, R. laticauda, Rivulus cf.robustus, Belonesox belizanus, Poeciliopsis gracilis, Xiphophorus andersi, X. maculatus, andOphisternon aenigmaticum. Eight species including one peripheral are present on both sides and constitute short penetrations across the barrier. At least nine species represent introductions, purposeful or accidental.

Conspecific intruders influence pair formation in a monogamous fish

In aquaria, monogamous Texas cichlid fish ( Cichlasoma cyanoguttatum) formed reproductive pairs significantly more often when another conspecific male (termed ‘intruder’) was visible behind a plexiglass partition. Without an intruder present, males often violently attacked and injured the female. Larger females, although attacked more frequently, were less prone to severe injuries. Pairs did not form when females were larger than males, irrespective of the presence of an intruder.

Temperature preference and tolerance of the spotted tilapia and Rio Grande cichlid

Temperature preference and tolerance of the spotted tilapia and Rio Grande cichlid

Ultrastructure of the dental epithelium during enameloid mineralization in a teleost fish, Cichlasoma cyanoguttatum

Secretory-stage inner dental epithilial cells (IDE) of tooth buds deposited an unmineralized, ectodermally-derived, enameloid collagen matrix. Pharyngeal plates bearing tooth buds were fixed: some were demineralized, others treated with guanidine-EDTA, then fixed and post-fixed in osmium tetroxide with potassium ferricyanide. Thin Epon sections were viewed in a Jeol 100B TEM. Nascent enameloid crystals were orientated parallel to the collagen fibres and attained widths of 200 nm. Enameloid collagen was absent in demineralized mature enameloid. The outer dental epithelial plasma membrane was deeply invaginated forming extensive channels associated with elongated fuzzy-coated vesicles. Four configurations of IDE cells were characterized by cellular constituents, including elongated granules, Golgi complexes, multivesicular bodies, large electron-dense granules and extracellular amorphous material which was also adjacent to cells containing few organelles associated with protein synthesis, within infoldings of ruffled apical membranes and multivesicular bodies. This material was considered to be resorbed enameloid collagen, not a secretory product.

The effects of mate separation on pair re-formation in the Texas cichlid fish ( [formula omitted

This study tested whether mated pairs of Texas cichlid ( Cichlasoma cyanoquttatum ) would reform and continue rearing their offspring after being separated for either one, four, or ten days. All pairs successfully re-formed after one day, while only 50% re-formed after 4 days. No pair re-formed after 10 days of separation. In successfully re-formed pairs, the female was always more aggressive than her mate, irrespective of whether the female was the resident or the returning individual. Aggressiveness seemed related to the female's attempt to control the male's parental behavior. For pairs which did not re-form, the resident parent, either the male or female, violently and continously attacked the returned mate.

Sexual Differences in Offspring Defense in a Monogamous Cichlid Fish

AbstractSolitary male and female Texas cichlids, Cichlasoma cyanoguttatum employ different tactics when defending their offspring. Males emphasize the lateral display against an intruder and make infrequent return visits to the young while the intruder is present. The female is more likely to attack, attempting to bite the intruder and also making frequent return visits to the offspring. These differences disappear with increasing age of the offspring as the male becomes more like the female with more violent attacks. Both defense systems appear effective, in the short term, against intruders.

Parental Division of Labor in a Monogamous Fish

Both parents of the monogamous Texas cichlid (Cichlasoma cyanoguttatum) participate in offspring care and territorial defense. These activities are typically synchronized, with and without intruders being present, such that only one parent is away from the offspring. During the egg and wriggler stage, the male spends more time patrolling the territory while the female devotes more time to offspring care. During the fry stage, both parents tend to remain with the offspring. Either sex can rear the offspring in the absence of the mate. With the removal of the mate, the female's activities remain largely unchanged while the male (in the absence of the female) becomes female-like. It appears as if the male adjusts his responses according to the activity of the female.

Field Observations of Parental Behavior of the Texas Cichlid Cichlasoma cyanoguttatum

Observations were made in the San Antonio and San Marcos rivers of central Texas on mated pairs of Texas Cichlids (Cichlasoma cyanoguttatum) both before and following fertilization. Monogamy was the only mating system observed with pair formation occurring prior to territory establishment. Following fertilization the paren- tal behaviors of both members of the mated pair were observed through all three stages of offspring development (eggs, wrigglers and fry). During the egg stage the male and female alternated in the performance of major parental responsibilities. Although male and female parental behaviors were qualitatively similar, quantitative sex differences were evident. The male spent more time patrolling the territory and the female spent more time in close proximity to and attending to the offspring. These quantitative dif- ferences, as well as the alternation of behaviors, diminished in the wriggler stage and largely disappeared by the fry stage. Somewhat paradoxically, at all stages of offspring development the female chased conspecific intruders more often and with faster chases.

Comparative Hematology of Lepomis microlophus and Cichlasoma cyanoguttatum

sunfish, Lepomis microlophus (Centrarchidae), and the Rio Grande perch, Cichlasoma cyanoguttatum (Cichlidae), from Hidalgo County, Texas, was studied from October 1974 to December 1975. There were no significant differences between the sexes in either species, but both species exhibited significant variation in blood parameters due to differences in standard length, reproductive condition or season. Change in reproductive condition apparently affected erythrocyte size. Seasonal changes in hemoglobin concentration and erythrocyte dimensions of L. microlophus were consistent with a pattern of increasing values with increasing water temperature. Erythrocyte size in C. cyanoguttatum may decrease with increasing water temperature. Hemoglobin concentration of the two species was similar, but L. microlophus had a larger number of erythrocytes and less hemoglobin per erythrocyte than C. cyanoguttatum. Comparative data suggest that the magnitude of difference in the hematology of L. microlophus and C. cyanoguttatum is no greater than that which exists between species of Lepomis.

The enhancement of the alkaline Bohr effect of some fish hemoglobins with adenosine triphosphate

The oxygen equilibria of the hemoglobins of one holostean fish, the spotted gar ( Lepisosteus osculatus), and of four teleost fish, the carpsucker ( Carpiodes carpio), the small mouth buffalo fish ( Ictiobus bubalus), the Rio Grande cichlid ( Cichlasoma cyanoguttatum), and the redear sunfish ( Lepomis microlophus), have been measured as a function of pH in the presence and absence of ATP. The oxygen equilibria of the teleost hemoglobins in the presence of 200 μ m ATP can be superimposed within experimental error upon the data obtained in the absence of ATP by a simple downward shift of the pH scale by 0.5 unit. Thus the effects of proton and ATP binding appear equivalent: Both can be interpreted in terms of a two-state allosteric model in which binding occurs preferentially to the low-affinity T-state. The oxygen affinities of each of the teleost hemoglobins approach asymptotically a maximal value at high pH. Although these high affinities are associated with decreased cooperativity of oxygen binding, as reflected by the Hill coefficient n, the asymptotic value of n never appears lower than 1.2 to 1.4. This indicates that the data cannot be completely described in terms of a single high-affinity R-state in alkaline solution: At least two different conformations are required. The oxygen affinity of the spotted gar hemoglobin, like that of each of the teleost hemoglobins, reaches a maximal value (minimal value of log PO 2 for half-saturation) above pH 8, but unlike teleost hemoglobins, the Hill coefficient reaches maximal values of 2.6 to 2.7 at high pH. The data in the absence of ATP are superimposable on the data in its presence by a downward shift of the pH scale by 0.25 unit. The measurement of the Bohr effect ( Δlog P 30 ΔpH ) in the presence and absence of ATP shows that the Bohr effect in each of the hemoglobins is substantially enhanced by organic phosphates, as it is in mammalian hemoglobins. The extent of the enhancement of the Bohr effect by 200 μ m ATP for each of the hemoglobins is approximately the same in the range pH 6.7 to 7.3 (increase in Δlog P 50 ΔpH ~ 0.3 ). This is a direct consequence of the equivalence of the linked-function relationship to the effects of ATP and proton binding on oxygenation.

GENETIC VARIATION AND SPECIATION IN NEW WORLD CICHLIDS.

In both the New and Old World, endemism in freshwater fishes of the family Cichlidae presents novel problems in differentiation and speciation (Fryer and Iles, 1972; Trewavas et al., 1972; Greenwood, 1974). In the New World, at least three undescribed forms are endemic to the Cuatro Cienegas Basin, Coahuila, Mexico (Taylor and Minckley, 1966; Minckley, 1969; La Bounty, 1974). The most abundant and widely distributed of the endemic forms possesses very fine pharyngeal teeth and light supporting musculature, and feeds primarily upon algae and detritus. Occurring with less abundance and more limited distribution, is a form characterized by thick heavy pharyngeal teeth used primarily for feeding upon snails. Upon external examination, the two forms are indistinguishable. The distribution and abundance of a third endemic is very restricted. It is presumably predatory in habit, and differs markedly in shape and dentition from the other two types (Taylor and Minckley, 1966; La Bounty, 1974). The occurrence of these endemic fishes within a limited geographic area is reminiscent of certain African lake cichlids (Fryer and Iles, 1972). Although the ancestoral form is not known, a widely distributed species, Cichlasoma cyanoguttatum (Baird and Girard) has invaded portions of the Cuatro Cienegas Basin in recent years, and occurs sympatrically with the endemic species in several places. Hybrids between C. cyanoguttatum and the two endemics are rare (La Bounty, 1974).

The hemoglobins of a fresh-water teleost, Cichlasoma cyanoguttatum (Baird and Girard). II. Subunit structure and oxygen equilibria of the isolated components

Three major components constitute at least 80% of the total hemoglobin in hemolysates of the Rio Grande cichlid, Cichlasoma cyanoguttatum. All three of these appear to share a common β chain. Two components have unique α chains, and the other component has both of these unique α chains. Two of the major components have identical oxygen equilibria. The effects of pH (Bohr effect) and of adenosine triphosphate are the same for each of the three components. Although one of the components has a slightly higher oxygen affinity than the other two the effects of pH and of adenosine triphosphate appear to be indistinguishable in the different components. The Hill coefficient, n, is pH-dependent for all components. The data indicate that the ion exchange chromatography was without effect on the oxygen-binding properties. The oxygen equilibria of the components cannot be interpreted in terms of dimers and appear to require a tetrameric structure of the hemoglobin in the concentration range studied.

The hemoglobins of a fresh-water teleost, Cichlasoma cyanoguttatum (Baird and Girard)—I. The effects of phosphorylated organic compounds upon the oxygen equilibria

1.1. Adenosine triphosphate (ATP) was found to be the major phosphorylated organic compound in the red cells of the teleost, Cichlasoma cyanoguttatum.2.2. Addition of ATP to phosphate-free solutions of hemoglobin decreases the oxygen affinity, increases the Bohr effect and modifies heme-heme interaction.3.3. The effects of DPG and ADP are similar but much smaller than the effect of ATP; cyclic AMP has no effect.

Pituitary-thyroid relationship during development in the teleost Herichthys cyanoguttatus: A histophysiologic study

Early developmental stages of the teleost Herichthys cyanoguttatus were reared in tap water or in 0.033% thiourea solution. In the thyroid, small amounts of colloid are secreted from the 2nd day after hatching, with an apparent climax of colloid production by the 5th day. Histologic differences between the thyroid of control and experimental fish are evident on the 4th day after hatching and can be interpreted as the establishment of a pituitary-thyroid feed-back relationship. Very faint aldehyde fuchsin positive (A.F.+) ve cells are present in the pituitary of some fish from the 2nd day after hatching. Differences between the pituitaries of control and experimental fish become evident 2 weeks after hatching: at this time the pituitaries of thiourea-treated fish are enlarged and contain an increased number of A.F.+ ve cells which indicates that these cells include the thyrotrophs. The development of the swim bladder, melanophores, and skin were also affected by thiourea.

The Lateral-Line System in the Rio Grande Perch, Cichlasoma cyanoguttatum (Baird and Girard)

The lateral-line system of Cichlasoma cyanoguttatum is similar to that of other perciforms but there are many peculiarities. The tubes of the lateralis scales do not make contact with each other but the innervation of the organs in this part of the system is normal. The exter- nal morphology and osteological components of the system are described in detail and compared with that of serranids and centrachids; the text is copiously augmented with illustrations. The lozenge-shaped canal neuromasts are in general like those of sunfishes but much larger. The sensory cells, unlike most of the cells seen in other fishes, bear multiple sensory hairs. All of the supporting cells penetrate to the free surface of the organ and intercellular bridges connect each with the others, thus forming a kind of syncytium. Cichlasoma cyanoguttatum is the only member of the family Cichlidae known to occur naturally in continental United States. Its range extends eastward from the Rio Grande in Texas as far north as the Rio Colorado near Austin. Material for this study was col- lected from the Blanco River, 25 miles northwest of San Marcos and from San Marcos Springs, Hayes County on July 14, 1958. Dr. Kirk Strawn of Lamar Institute of Technology, Beaumont, Texas, assisted in the collecting and Dr. G. A. Moore of Oklahoma State University offered helpful criticisms. I am grateful for their assistance. Several specimens were fixed in PFA3, one of Allen's modifica- tions of Bouin's fluid, and others in 10 per cent formalin. Three of the formalin-fixed specimens were stained by the alizarin method of Hollister (1934). In addition, four large specimens were packed in dry ice and subsequently disarticulated for bone study. Other formalinized fish were dried by means of jets of air and the canal system injected with India ink. Innervation was determined by gross dissection under the lens of a stereomicroscope. The lachrymal bone was chosen for microscope sections because of its constancy and ease of removal. Material for sectioning was decalcified in two per cent hydrochloric acid, embedded in pyroxylin and cut at five microns. Some sections were stained with iron hematoxylin and others wifth Mallory's triple connective tissue stain; all were mounted in picrolyte. Measurements were taken by means of a filar micrometer mounted on a compound microscope. Drawings were made with the assistance of a camera lucida. EXTERNAL MORPHOLOGY In its external appearance the cephalic lateral-line system of