Egg density and salinity influence filial cannibalism in common gobies

2017 ◽  
Vol 71 (11) ◽  
Author(s):  
Martin Vallon ◽  
Katja U. Heubel
2008 ◽  
Vol 4 (2) ◽  
pp. 160-162 ◽  
Author(s):  
Hope Klug ◽  
Kai Lindström

Filial cannibalism (the consumption of one's own offspring) is thought to represent an adaptive strategy in many animals. However, little is known about the details of which offspring are consumed when a parent cannibalizes. Here, we examined patterns of within-brood filial cannibalism in the sand goby ( Pomatoschistus minutus ). Males spawned sequentially with two females, and we asked whether males cannibalized selectively with regard to egg size or the order in which eggs were received. Males preferentially consumed the larger eggs of the second female they spawned with. Because larger eggs took longer to hatch, and because female 2's eggs were up to 1 day behind those of female 1, such preferential cannibalism might allow males to decrease the time spent caring for the current brood and re-enter the mating pool sooner. More work is needed to understand the fitness consequences of such selective cannibalism.


1985 ◽  
Vol 117 (7) ◽  
pp. 819-828 ◽  
Author(s):  
Ann E. Hajek ◽  
Donald L. Dahlsten

AbstractPopulations of Scolytus multistriatus (Marsham) from two areas of California were sampled in 1979 to investigate various factors influencing mortality. English-elm bolts (Ulmus procera Salisb.) ranging between 2.0 and 12.9 cm in diameter yielded mean mortalities from 49.1 to 86.0%. Mortality was highly correlated with egg density for branch samples from 7.0 to 12.9 cm in diameter. The minimum acceptable elm-branch diameter (2.8 cm) was attacked only during the first sampling period (mid-May to mid-June). Branch diameter, and therefore bark thickness, demonstrated a strong positive relationship with the density of S. multistriatus eggs, attacks, gallery lengths, and emerged adults. Gallery length density was positively correlated with attack density. At low attack densities in small-diameter branches, mean gallery lengths were shorter.


Behaviour ◽  
2011 ◽  
Vol 148 (2) ◽  
pp. 247-264 ◽  
Author(s):  
Masanori Kohda ◽  
Nobuhiro Ohnishi ◽  
Noboru Okuda ◽  
Tomohiro Takeyama ◽  
Omar Myint

AbstractFilial cannibalism, eating one's own viable offspring, is accepted as an adaptive response to trade-offs between current and future reproduction. Theoretical models predict that high mate availability may induce more filial cannibalism, but this prediction is rarely tested. To examine this prediction, we performed laboratory experiments using the nest breeding goby Rhinogobius flumineus. Subject males were allowed to mate with a gravid female and care for the broods. A separate gravid female housed in a small cage (stimulus-female) was shown to the subject males at one of three different points during the brood cycle: prior to spawning, within 1 day after spawning and 1 week after spawning. Empty cages were shown as a control. Males that were shown the stimulus-female before spawning cannibalised more eggs than control males. In contrast, males that were shown the stimulus-females after spawning cannibalised as few eggs as control males did. Additionally, males that were shown the stimulus-female prior to spawning did not court females more intensively than other males. Thus, we suggest that the presence of an additional mate, rather than energy expenditure associated with courtship directed toward an additional mate, can facilitate males to cannibalise their eggs.


Insects ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 707
Author(s):  
Qi Yao ◽  
Huining Zhang ◽  
Long Jiao ◽  
Xiaoming Cai ◽  
Manqun Wang ◽  
...  

Tea leafhopper (Empoasca onukii Matsuda) is amongst the key pests in tea plantations around the East Asian region. Stereomicroscopy is a conventional method used for detecting tea leafhopper eggs by dissecting the tender tissues. However, there is a need for a faster and more efficient method to directly observe and investigate intact eggs within tea shoots. The absence of a proven method limits research efforts for determining the oviposition behavior of E. onukii. Herein, we applied the blue light detection method (BLDM), a technique recently developed for other species, in order to detect E. onukii eggs directly and non-destructively within the tender shoot. In addition, we compared BLDM against the traditional stereomicroscope detection method (SMDM) for four tea cultivars. Notably, our results revealed that BLDM was precise and effective in measuring the egg laying quantity of E. onukii on intact tea shoots. Neither tea cultivars nor egg density in the tender shoot significantly affected the accuracy of BLDM. Furthermore, biological characteristics that have rarely been reported previously for E. onukii were investigated using the BLDM, including zygote duration, ovipositional rhythm, egg distribution within the tender shoot, and in different leaf positions, numbers of eggs laid by a single female daily, and laid by the entire generation. Therefore, these findings provide insights into the basic and theoretical evidence for the strategy and mechanism associated with the oviposition behavior of E. onukii.


1990 ◽  
Vol 122 (3) ◽  
pp. 555-562 ◽  
Author(s):  
R.F. Shepherd ◽  
T.G. Gray

AbstractEggs of western blackheaded budworm, Acleris gloverana (Walsingham), are laid on the lower surface of western hemlock, Tsuga heterophylla (Raf.) Sarg., needles. A comparison was made of the following measures of sample branch size as a basis for expressing egg density: fresh branch weight, branch area, total twig length, branch volume, and number of buds. The criteria for selection of these measures were as follows: correlations of branch size with dry needle weight, variances of egg density and their relative contribution to sample size, and ease of measurement. Fresh branch weight was the best choice. A sequential sampling system was developed on this basis and was related to a scale of predicted defoliation. In addition, a transformation was provided for use in data analysis.


1998 ◽  
Vol 55 (12) ◽  
pp. 2608-2621 ◽  
Author(s):  
N H Augustin ◽  
D L Borchers ◽  
E D Clarke ◽  
S T Buckland ◽  
M Walsh

Generalized additive models (GAMs) are used to model the spatiotemporal distribution of egg density as a function of locational and environmental variables. The main aim of using GAMs is to improve precision of egg abundance estimates needed for the annual egg production method. The application of GAMs requires a survey design with good coverage in space and time. If the only results available are from less optimal survey designs, they can be improved by using historical data for spawning boundaries. The method is applied to plankton egg survey data of Atlantic mackerel (Scomber scombrus) in 1995. The GAM-based method improves the precision of estimates substantially and is also useful in explaining complex space-time trends using environmental variables.


2010 ◽  
Vol 29 (1) ◽  
pp. 153-159 ◽  
Author(s):  
Omar Myint ◽  
Hajime Tsujimoto ◽  
Nobuhiro Ohnishi ◽  
Tomohiro Takeyama ◽  
Masanori Kohda

Evolution ◽  
1989 ◽  
Vol 43 (1) ◽  
pp. 158 ◽  
Author(s):  
Christopher W. Petersen ◽  
Karen Marchetti
Keyword(s):  

2020 ◽  
Vol 202 ◽  
pp. 12016
Author(s):  
Martini Martini ◽  
Zufri Armen ◽  
Kusariana Nissa ◽  
Hestiningsih Retno ◽  
Yuliawati Sri ◽  
...  

Dengue Hemorrhagic Fever (DHF) is a disease caused by Dengue virus. In 2016, the number of DHF patients in areas of Health services of Rowosari was 247 cases, IR 289.6/100.000 populations and the highest number of the patients was from Meteseh Village. The most usual mechanism happened in the vertical transmission, transovarial infection, from adult mosquito to the egg. The study was conducted to describe of entomological status of House Index (HI), Container Index (CI), Breteau Index (BI), House index (HI), Ovitrap Index (OI) of larvae as well as transovarial infection in Aedes sp. The research method was descriptive method by conducting test to the entomology status of DHF incidence. Based on the survey in Meteseh sub-village (XVI), a result found that average House Index 8.99%, Container Index 2.88%, Breteau Index 16.40%, HI 8,99 Ovitrap Index 35.46% with the egg density at 1.023 eggs. The identified mosquitoes were 30, and from the identification result of Aedes sp., two Aedes species were found, 28 Aedes aegypti,and only 2 Aedes albopictus. The transovarial infection in Aedes sp. using ELISA method was found 6 mosquito samples which were positive of dengue virus, with the detail in neighborhood 01 (1 sample), neighborhood 02 (2 samples), neighborhood 03 (3 samples). DHF in Meteseh Sub village in Semarang City was probably happened because correlated with transovarial infection.


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