Study on Size Dimorphism in Six Juliform Millipedes | Chapter 10 | New Visions in Biological Science Vol. 8

 

The goal of this work was to explain Sexual Size Dimorphism (SSD) in the diplopod genera Bicoxidens, Doratogonus, Harpagophora, Julomorpha, and Orthoporoides, in which length, width, and rings are the primary components of interspecific variation. The data sets for B. brincki Schubart, [1] D. annulipes Carl, 1917, H. spirobolina (Karsch, 1881), J. hilaris Attems, 1928, J. panda (Attems, 1928), and O. tabulinus (Attems, 1914) were checked for normality. Male and female lengths differed in all species except J. hilaris, which had differing widths. Juliform millipedes appear to have shrunk in size through time, and this study reveals an intriguing finding: larger species have sexual dimorphism based on length, while smaller species have sexual dimorphism based on width. This is because of the limits imposed by a cylindrical body form, which may be modified more forcefully by reducing width than than length.

Author(S) Details

Mark Cooper
School of Animal, Plant & Environmental Sciences, University of the Witwatersrand, Johannesburg 2050, South Africa

View Book:- https://stm.bookpi.org/NVBS-V8/article/view/5385

Longer Males Determined with Positive Skew and Kurtosis in Centrobolus (Diplopoda: Spirobolida: Pachybolidae) | Chapter 8 | New Visions in Biological Science Vol. 8

 In the diplopod genus Centrobolus, sexual size dimorphism (SSD) displays a positive connection with body size width. The key components of interspecific variation in diplopod species are length, width, and rings. In six species, interspecific size variation was estimated with the goal of testing data sets for skewness and kurtosis. Positive skew and positive kurtosis were found in 28 of the values, while negative skew and negative kurtosis were found in 8 of the values. The width was positively skewed in six situations and negatively skewed in four. Except for C. titanophilus, all six species had a positive length skew. When there existed size assortative mating behaviour, it was considered that longer males had a higher reproductive success due to a female preference for the greater size.

Author(S) Details

Mark Cooper
School of Animal, Plant & Environmental Sciences, University of the Witwatersrand, Johannesburg 2050, South Africa

View Book:- https://stm.bookpi.org/NVBS-V8/article/view/5382