Tag: genitalia

Beetle named after actress & biologist Isabella Rossellini for her series about animals

A new species of beetle with remarkably long genitalia that hint at a curious evolutionary “sexual arms race” has been described from Malaysian Borneo.

The new insect was named after actress and biologist Isabella Rossellini in honour of her stage shows and Webby Award-winning series of films about animal reproduction, featured on SundanceTV.

The species is described by scientists Menno Schilthuizen and Iva Njunjic of Naturalis Biodiversity Center and Universiti Malaysia Sabah, and Michel Perreau, Sorbonne Université, Paris. Their paper is published in the open access journal ZooKeys.

The new species, Ptomaphaginus isabellarossellini, finds a place among the 30 known species of round fungus beetles (subfamily Cholevinae) recorded by the authors from the island of Borneo. Of these, there are a total of 14 which had remained unknown to science until now.

The reason why the scientists named this particular species after the famous actress is its genitalia. The beetle’s penis carries a long, whip-like thread, called flagellum, whereas the female has a similarly long tube leading up to a sperm storage organ.

Lead author Menno Schilthuizen, who himself has previously released a simultaneously educative and entertaining book about the evolution of genitals, says that such exaggerated male and female genitalia often betray an “evolutionary sexual arms race”.

On the male side, natural selection favours longer genitalia because of the ability to directly reach the female’s sperm storage organ. However, female beetles would rather retain their right to favour the DNA of a certain mate over the rest. The upshot is that, over long periods of evolution, penises get longer and vaginas get deeper. Similar evolutionary genital exaggeration is also known in rove beetles and ducks.

“This is better than winning the Oscar,” says honoured Isabella Rossellini.

The Italian-born actress, filmmaker, author, philanthropist, and model has even featured the new beetle in her new Link Link Circus stage shows. Dealing with animal behaviour, the series will be touring theaters in Europe this fall.

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Original source:

Schilthuizen M, Perreau M, Njunjic I (2018) A review of the Cholevinae from the island of Borneo (Coleoptera, Leiodidae). ZooKeys 777: 57-108. https://doi.org/10.3897/zookeys.777.23212

The first long-horned beetle giving birth to live young discovered in Borneo

A remarkably high diversity of the wingless long-horned beetles in the mountains of northern Borneo is reported by three Czech researchers from the Palacký University, Olomouc, Czech Republic. Apart from the genera and species new to science, the entomologists report the first case of reproduction by live birth in this rarely collected group of beetles. The study was published in the open access journal ZooKeys.

Generally, insects are oviparous, which means that their females lay eggs and the embryonic development occurs outside the female’s body. On the other hand, ovoviviparous species retain their eggs in their genital tracts until the larvae are ready to hatch. Such mode of reproduction is a relatively rare phenomenon in insects and even rarer within beetles, where it has been reported for a few unrelated families only.

The long-horned beetles are a family, called Cerambycidae, comprising about 35,000 known species and forming one of the largest beetle groups.

“We studied the diversity of the rarely collected wingless long-horned beetles from Borneo, which is one of the major biodiversity hotspots in the world,” says main author and PhD student Radim Gabriš. “The mountains of northern Borneo, in particular, host a large number of endemic organisms.”

The scientists focused on the group which nobody had studied in detail for more than 60 years. They found surprisingly high morphological diversity in this lineage, which resulted in the descriptions of three genera and four species new to science.

“During a dissection of female genitalia in specimens belonging to the one of the newly described genera, named Borneostyrax, we found out that two females contained large larvae inside their bodies,” recalls Radim Gabriš. “This phenomenon have been known in a few lineages of the related leaf beetles, but this is the first case for the long-horned beetles.”

However, according to the authors, the modes of reproduction remain unknown for many beetle lineages besides Cerambycidae, so the ovoviviparity might be, in fact, much more common. Further detailed studies are needed for better understanding of the reproductive strategy in this group.

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Original source:

Gabriš R, Kundrata R, Trnka F (2016) Review of Dolichostyrax Aurivillius (Cerambycidae,Lamiinae) in Borneo, with descriptions of three new genera and the first case of (ovo)viviparity in the long-horned beetles. ZooKeys 587: 49-75. doi: 10.3897/zookeys.587.7961