Parental male and female convict cichlids assess and respond to threats differently depending on intruder species

2021 ◽  
pp. 104396
Author(s):  
Natalie A. van Breukelen ◽  
Nicholas Santangelo
2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Timothy Paciorek ◽  
Leese Joseph

Abstract Biparental care has evolved to ensure successful rearing of offspring. However, separation during periods of care can lead to conflicts that might negatively impact pair bonds and offspring care. In this study, pair-bonded convict cichlids (Amatitlania nigrofasciata) were observed for changes in behavior toward their partners and offspring before and after a period of separation. Males and females were designated either as a Resident (remain with offspring) or Removed (separated from partner and offspring for 5 days) individual. Behaviors between partners and toward offspring were measured before and after separation, and compared to the levels of behavior of control pairs (never separated), as well as individuals introduced to a novel partner instead. Cortisol levels of Resident male and female A. nigrofasciata were assayed using water-borne hormone collection before and after separation. Aggression between pair bond members did increase following reintroduction, but did not lead to the termination of pair bonds. Resident females showed more aggression to novel partners than Resident males. Offspring care decreased in both Resident and Removed females. Experimental pairs decreased the amount of time spent interacting with intruders. Cortisol levels were significantly higher among experimental pairs compared with control pairs that did not experience a separation. Females (both control and experimental) showed small, yet significant increases in cortisol levels, while both control and experimental males did not. These results suggest that while pair bonds appear resilient, prolonged separations influence pair bond and parental care dynamics, both behaviorally and hormonally, and require pairs to re-establish roles, resulting in less time caring for offspring.


1993 ◽  
Vol 71 (5) ◽  
pp. 960-967 ◽  
Author(s):  
Robert W. Mackereth ◽  
Miles H. A. Keenleyside

In many biparental species a sex difference in parental investment in a brood before fertilization, such as establishing a breeding territory or preparing a nest, may be an important component of the overall pattern of parental investment. Prefertilization investment patterns have been described for several species of biparental cichlid fishes, but there are discrepancies in the descriptions for the convict cichlid, Cichlasoma nigrofasciatum. This study describes quantitatively the prespawning behaviour of male and female convict cichlids and examines the influence on their behaviour of limiting the number of available spawning sites. The results indicate that pair formation begins several days before spawning when the female begins to follow a male and chase other females away from him. The pair then begins to spend more time in a smaller area where spawning eventually occurs. The breeding territory is usually established by the pair on the day of spawning. There was little difference in the pattern of prespawning behaviour offish with abundant versus limited spawning sites. It appears that neither sex will establish a territory until the female is ready to spawn and the pair has formed.


Author(s):  
R. F. Bils ◽  
W. F. Diller ◽  
F. Huth

Phosgene still plays an important role as a toxic substance in the chemical industry. Thiess (1968) recently reported observations on numerous cases of phosgene poisoning. A serious difficulty in the clinical handling of phosgene poisoning cases is a relatively long latent period, up to 12 hours, with no obvious signs of severity. At about 12 hours heavy lung edema appears suddenly, however changes can be seen in routine X-rays taken after only a few hours' exposure (Diller et al., 1969). This study was undertaken to correlate these early changes seen by the roengenologist with morphological alterations in the lungs seen in the'light and electron microscopes.Forty-two adult male and female Beagle dogs were selected for these exposure experiments. Treated animals were exposed to 94.5-107-5 ppm phosgene for 10 min. in a 15 m3 chamber. Roentgenograms were made of the thorax of each animal before and after exposure, up to 24 hrs.


Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs

Gonadotroph cell adenomas of the pituitary are infrequent in human patients and are not invariably associated with altered gonadal function. To date, no animal model of this tumor type exists. Herein, we describe spontaneous gonadotroph cell adenomas in old male and female Sprague-Dawley rats by histology, immunocytology and electron microscopy.The material consisted of the pituitaries of 27 male and 38 female Sprague Dawley rats, all 26 months of age or older, removed at routine autopsy. Sections of formal in-fixed, paraffin-embedded tissue were stained with hematoxylin-phloxine-saffron (HPS), the PAS method and the Gordon-Sweet technique for the demonstration of reticulin fibers. For immunostaining, sections were exposed to anti-rat β-LH, anti-ratβ-TSH, anti-rat PRL, anti-rat GH and anti-rat ACTH 1-39. For electron microscopy, tissue was fixed in 2.5% glutaraldehyde, postfixed in 1% OsO4 and embedded in epoxy-resin. Tissue fixed in 10% formalin, embedded in epoxy resin without osmification, was used for immunoelectron microscopy.


Author(s):  
Conly L. Rieder ◽  
Frederick J. Miller ◽  
Edwin Davison ◽  
Samuel S. Bowser ◽  
Kirsten Lewis ◽  
...  

In this abstract we Illustrate how same-section correlative light and high voltage electron microscopy (HVEM) of serial 0.25-0.50-μm sections can answer questions which are difficult to approach by EM of 60-100 nm sections.Starfish (Pisaster and Asterlas) eggs are fertilized at meiosis I when the oocyte contains two maternal centrosomes (e.g., asters) which form the poles of the first meiotic spindle. Immediately after fertilization a sperm aster is assembled in the vicinity of the male pronucleus and persists throughout meiosis. At syngamy the sperm aster splits to form the poles of the first mitotic spindle. During this time the functional and replicative properties of the maternal centrosome, inherited from the last meiotic division, are lost. The basis for this differential stability, of male and female centrosomes in the same cytoplasm, is a mystery.


1979 ◽  
Vol 10 (4) ◽  
pp. 246-248 ◽  
Author(s):  
Peter B. Mueller ◽  
Marla Adams ◽  
Jean Baehr-Rouse ◽  
Debbie Boos

Mean fundamental frequencies of male and female subjects obtained with FLORIDA I and a tape striation counting procedure were compared. The fundamental frequencies obtained with these two methods were similar and it appears that the tape striation counting procedure is a viable, simple, and inexpensive alternative to more costly and complicated procedures and instrumentation.


2020 ◽  
Vol 63 (7) ◽  
pp. 2054-2069
Author(s):  
Brandon Merritt ◽  
Tessa Bent

Purpose The purpose of this study was to investigate how speech naturalness relates to masculinity–femininity and gender identification (accuracy and reaction time) for cisgender male and female speakers as well as transmasculine and transfeminine speakers. Method Stimuli included spontaneous speech samples from 20 speakers who are transgender (10 transmasculine and 10 transfeminine) and 20 speakers who are cisgender (10 male and 10 female). Fifty-two listeners completed three tasks: a two-alternative forced-choice gender identification task, a speech naturalness rating task, and a masculinity/femininity rating task. Results Transfeminine and transmasculine speakers were rated as significantly less natural sounding than cisgender speakers. Speakers rated as less natural took longer to identify and were identified less accurately in the gender identification task; furthermore, they were rated as less prototypically masculine/feminine. Conclusions Perceptual speech naturalness for both transfeminine and transmasculine speakers is strongly associated with gender cues in spontaneous speech. Training to align a speaker's voice with their gender identity may concurrently improve perceptual speech naturalness. Supplemental Material https://doi.org/10.23641/asha.12543158


1980 ◽  
Vol 45 (2) ◽  
Author(s):  
Ronald L. Schow ◽  
Michael A. Nerbonne

In the February 1980 issue of this journal, the report by Ronald L. Schow and Michael A. Nerbonne ("Hearing Levels Among Elderly Nursing Home Residents") contains an error. On page 128, the labels "Male" and "Female" in Table 2 should be reversed.


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