Researchers find homes harbor nearly 500 different species of arthropods

JANUARY 20, 2016

by Brett Smith

We all know there’s a random ant or two roaming our house right now, looking for a dropped crumb. Or, a cobweb spider – doing what else – making a cobweb.

But what if it told you there are about 500 different kinds of bugs skittering around your happy home? Well, it’s true – according to a new study in the journal PeerJ.

“This was exploratory work to help us get an understanding of which arthropods are found in our homes,” study author Matt Bertone, an entomologist at North Carolina State University, said in a statement. “Nobody had done an exhaustive inventory like this one, and we found that our homes host far more biodiversity than most people would expect.”

In the study, researchers visited 50 houses within 30 miles of Raleigh, NC. Across all 50 homes, the scientists recognized nearly 580 several morphospecies of arthropod from more than 300 arthrodpod families. The team found homes had between 32 and 211 morphospecies, a term used to define animal types that are easily separable by morphological factors that are noticeable to individuals without extensive taxonomic training. The study team also found between 24 and 128 distinct families. The most commonly gathered groups were beetles, flies, ants and book lice.

“While we collected a remarkable diversity of these creatures, we don’t want people to get the impression that all of these species are actually living in everyone’s homes,” Bertone said. “Many of the arthropods we found had clearly wandered in from outdoors, been brought in on cut flowers or were otherwise accidentally introduced. Because they’re not equipped to live in our homes, they usually die pretty quickly.”

For example, the researchers discovered gall midges in many homes. These tiny bugs need to feed on outdoor plants and quickly die once they enter our homes.

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Fossilized Brains Shed Light on Arthropod Family Tree

by Laura Geggel, Staff Writer | May 07, 2015 03:14pm ET

The shiny, fossilized brains of two ancient sea-monsterlike creatures are helping researchers understand how the ancestors of modern-day arthropods, such as scorpions and lobsters, evolved, as shown in a new study.

The new research focuses on an oval structure, called the anterior sclerite, found in the heads of ancient arthropods. The anterior sclerite has long baffled researchers, especially because some prehistoric arthropods have it while others don't, and its location in the head changes, depending on the quality of the fossil.

But now, fossilized brains have helped solve that mystery. An analysis of the anterior sclerites in two arthropod fossils, both more than 500 million years old, indicates that the structures were associated with the creatures' bulbous eyes. The findings provide evidence that these oval structures were associated with nerves originating in the anterior region of the brain, according to the study. 

Continued ...

8 Quirky Species Discovered in Lava-Tube Caves

Eight new arthropod species and a new hibernating site for Townsend's big-eared bats have been discovered in New Mexico lava-tube caves, adding to the limited ecologic understanding of this unique habitat type.

Lava-tube caves form when underground offshoots of lava flows spill downslope but cool around the edges, emptying hollow, artery like cavities that can span many miles long. More than 200 such caves extend beneath El Malpais National Monument in western New Mexico and support ecosystems distinct from more commonly known limestone caves, which develop different shapes and air current patterns.

The resource management team of El Malpais National Monument conducts routine, large-scale inventories of the caves to document roosting and hibernating sites of bats, and the habitat range of other animal species. But these sweeping surveys often overlook more elusive species hiding in remote corners of the caves.

To develop a more comprehensive inventory of the national monument's animal life, a team of researchers based at Northern Arizona University conducted a systematic study of 11 caves aimed to document all inhabitants of those caves. The results were recently published in the summer issue of the journal Park Science.

Continued

500-Million-Year-Old Sea Creature With Limbs Under Its Head Unearthed

Tia Ghose, LiveScience Staff Writer

Date: 27 February 2013 Time: 01:00 PM ET

Scientists have unearthed extraordinarily preserved fossils of a 520-million-year-old sea creature, one of the earliest animal fossils ever found, according to a new study.

CREDIT: Yie Jang (Yunnan University) 

The fossilized animal, an arthropod called a fuxhianhuiid, has primitive limbs under its head, as well as the earliest example of a nervous system that extended past the head. The primitive creature may have used the limbs to push food into its mouth as it crept across the seafloor. The limbs may shed light on the evolutionary history of arthropods, which include crustaceans and insects.

"Since biologists rely heavily on organization of head appendages to classify arthropod groups, such as insects and spiders, our study provides a crucial reference point for reconstructing the evolutionary history and relationships of the most diverse and abundant animals on Earth," said study co-author Javier Ortega-Hernández, an earth scientist at the University of Cambridge, in a statement. "This is as early as we can currently see into arthropod limb development."

Continued:  http://www.livescience.com/27504-cambrian-arthropod-fossil-discovered.html

Three New Arthropod Species Have Been Found in the Maestrazgo Caves in Teruel

ScienceDaily (Nov. 27, 2012) — A team of scientists from the University of Navarra and the Catalan Association of Biospeleology have discovered three new collembolan species in the Maestrazgo caves in Teruel, Spain. Their description has been published in the Zootaxa journal. These minute animals belong to one of the most ancient animal species on the planet.

The Maestrazgo caves in Teruel are located in a region of the Iberian Range where fauna has not been the subject of much study. It is a very isolated region since its average altitude is between 1,550 m and 2,000 m asl and its climate can be described as "almost extreme" experiencing temperatures of between -40°C and -25°C. Inside the caves, however, the temperatures remain constant at between 5°C and 11°C.

"Studying fauna in the caves allows us to expand on our knowledge of biodiversity. In the case of the three new collembolan species that we have found in Teruel, they are organisms that have survived totally isolated for thousands of years. Having 'relatives' on the surface means they act like relics from the past that have survived the climate change taken place on the outside of the caves," as explained by Enrique Baquero, who carried out a taxonomic study along with Rafael Jordana, both of whom are from the University of Navarra.

Read on:  http://www.sciencedaily.com/releases/2012/11/121127094113.htm

Are Our Bones Well Designed? Insects and Crabs Have a Leg Up On Us

ScienceDaily (Sep. 12, 2012) — Researchers from Trinity College Dublin have recently shown that the legs of grasshoppers and crabs have the ideal shape to resist bending and compression. If human leg bones were built the same way, they could be twice as strong.

"Like all Arthropods, grasshoppers and crabs have so called exoskeletons made from a very special material called cuticle," said Professor David Taylor, of the Trinity Centre for Bioengineering at Trinity College Dublin, Ireland. "This exoskeleton protects the animal like a knight's suit of armour. Recently we have shown that this cuticle is in fact one of the toughest natural materials."

Continued:  http://www.sciencedaily.com/releases/2012/09/120912084432.htm

Invisible fungi crucial for rainforest diversity

A complex network of fungi in the lower canopy could be one reason tropical rainforests are home to so many different types of insects, spiders and centipedes, say scientists.

They found that nearly half of these creatures – called arthropods – are largely dependent on an almost-invisible network of fungi that traps dead leaves that have fallen from the upper canopy.

When the researchers removed the fungi, both the numbers and diversity of arthropods dropped dramatically.

The findings could help conservationists figure out how to retain some level of arthropod diversity in managed landscapes like oil palm plantations, or logged forest.

The fungi branch through the lower canopy extending from the forest floor up to around 30 metres high, catching falling leaves wherever their strands go.

'These fungi are everywhere, and form a messy tangle in the forest understory. You can't really see it until you look for it. You're always looking past it, moving it out of the way as you walk through the forest,' explains Dr Jake Snaddon from the University of Oxford, lead author of the study.

This could be why, up until now, its importance was almost entirely overlooked.


Read more here ...

Walking cactus discovered in China

Walking cactus: Scientists have discovered what researchers are calling the missing link in China. The strange-looking walking cactus is thought to be the link between worm-like creatures and arthopods like spiders.

By Wynne Parry, LiveScience / February 25, 2011

Fossils of a 10-legged wormy creature that lived 520 million years ago may fill an important gap in the history of the evolution of insects, spiders and crustaceans.

The so-called walking cactus belongs to a group of extinct worm-like creatures called lobopodians that are thought to have given rise to arthropods. Spiders and other arthropods have segmented bodies and jointed limbs covered in a hardened shell.

Before the discovery of the walking cactus, Diania cactiformis, all lobopodian remains had soft bodies and soft limbs, said Jianni Liu, the lead researcher who is affiliated with Northwest University in China and Freie University in Germany.

"Walking cactus is very important because it is sort of a missing link from lobopodians to arthropods," Liu told LiveScience. "Scientists have always suspected that arthropods evolved from somewhere amongst lobopodians, but until now we didn't have a single fossil you could point at and say that is the first one with jointed legs. And this is what walking cactus shows." [Image of walking cactus fossil]

Leggy find

Liu and other researchers described the extinct creature based on three complete fossils and 30 partial ones discovered in Yunnan Province in southern China. The walking cactus had a body divided into nine segments with 10 pairs of hardened, jointed legs, and it measured about 2.4 inches (6 centimeters) long.

It's not clear how the leggy worm made its living. It could have used its tube-like mouth called a proboscis to suck tiny things from the mud, or it may have used its spiny front legs to grab prey, Liu said.

Clues to arthropod evolution are preserved in modern-day velvet worms, which are considered the only living relative to all arthropods. Once mistaken for slugs, these land-dwelling worms are almost entirely soft-bodied except for hardened claws and jaws.

Where spiders, insects and others came from

The discovery of the walking cactus helps fill in the evolutionary history between the velvet worms and modern arthropods, which, in terms of numbers and diversity, are the most dominant group of animals on the planet, according to Graham Budd, a professor of paleobiology at Uppsala University in Sweden, who was not involved in the current study.

The walking cactus is the first and only case of hardened, jointed limbs built for walking appearing in a creature that is not recognizable as an arthropod, Budd said.

But Budd is not convinced that, as the researchers argue, the walking cactus's hardened legs were passed directly down to modern arthropods.

"I am not persuaded that it is a direct ancestor or as closely related to living arthropods as they suggest," he told LiveScience. "I would like to see more evidence; the great thing is a lot more material keeps coming up."
For instance, it is possible that the walking cactus is less closely related to modern arthropods, and that hardened legs evolved multiple times. It is also possible that the bodies of primitive arthropods hardened before their legs did, Budd said.

New fossils, particularly from China, have helped clarify the evolutionary history of arthropods, and in the last decade or so, scientists have come to more consensus regarding that history, he added.

http://www.csmonitor.com/Science/2011/0225/Walking-cactus-discovered-in-China

Where Did Insects Come From? New Study Establishes Relationships Among All Arthropods

RIGHT: This animal, Speleonectes tulumensis, is from a group of rare, blind, cave-dwelling crustaceans called "remipedes." The new analysis in Nature shows that the remipedes are the crustaceans most closely related to the insects. Remipedes and insects together are now shown to be a sister group to all the other crustacea including the crabs, shrimps, and lobsters. (Credit: Simon Richards)

ScienceDaily (Feb. 22, 2010) — Since the dawn of the biological sciences, humankind has struggled to comprehend the relationships among the major groups of "jointed-legged" animals -- the arthropods. Now, a team of researchers, including Dr. Joel Martin and Dr. Regina Wetzer from the Natural History Museum of Los Angeles County (NHM), has finished a completely new analysis of the evolutionary relationships among the arthropods, answering many questions that defied previous attempts to unravel how these creatures were connected.

Their study is scheduled for publication in the journal Nature on Feb. 24.

Now, for the first time, science has a solid grasp of what those relationships are, and a framework upon which to build. The new study makes a major contribution to our understanding of the nature and origins of the planet's biodiversity. The paper's other researchers are Jerome C. Regier, Andreas Zwick and April Hussey from the University of Maryland Biotechnology Institute; Jeffrey W. Shultz of the University of Maryland's Department of Entomology; and Bernard Ball and Clifford W. Cunningham from Duke University's Department of Biology.

There are millions of distinct species of arthropods, including all the insects, crustaceans, millipedes, centipedes, spiders, and a host of other animals, all united by having a hard external shell and jointed legs. They are by far the most numerous, and most diverse, of all creatures on Earth -- in terms of the sheer number of species, no other group comes close. They make up perhaps 1.6 million of the estimated 1.8 to 1.9 million described species, dominating the planet in number, biomass, and diversity.

The economic aspects of arthropods are also overwhelming. From seafood industries worth billions of dollars annually to the world's economy, to the importance of insects as pollinators of ornamental and agriculturally important crops, to the medical role played by arthropods (e.g. as disease vectors and parasites), to biological control of introduced species, to their role in every known food web, to toxicology and biopharmaceuticals, arthropods are by far the planet's most important group of animals.

"We've never really known how arthropods, the most successful animals on Earth, evolved into the diversity we see today," said research scientist and co-author Dr. Regina Wetzer. "For me, what makes this study really exciting is getting such a solid understanding of how these animals are related, so that now we can better understand how they evolved."

Because of their amazing diversity, deciphering the evolutionary history and relationships among the major subgroups of arthropods has proven difficult. Scientists have tried using various combinations of features, in recent years including DNA sequences, to try to understand which groups are related through common ancestors. To date, those attempts have been stymied by the sheer number of species and wild shape variations between the various groups.

One of the most important results of this new study is support for the hypothesis that the insects evolved from a group of crustaceans. So flies, honeybees, ants, and crickets all branched off the arthropod family tree from within the lineage that gave rise to today's crabs, shrimp, and lobsters. Another important finding is that the "Chelicerata" (a group that includes the spiders, scorpions, ticks, and mites) branched off very early, earlier than the millipedes, centipedes, crustaceans, and insects. That means that the spiders, for example, are more distantly related to the insects than many researchers previously thought.

This team approached the problem of illuminating the arthropod family tree by using genetic data (DNA sequences) obtained from 75 species carefully selected to sample the range of arthropod diversity. Many previous analyses were based on the sequences of a handful of genes. The researchers in this study, knowing the daunting diversity they faced, used DNA sequence information from as many genes as they could. In the end, they were able to apply data from 62 protein-coding genes to the problem, leading to an extremely well-supported analysis.

"The Museum's collection of arthropods, and in particular its collection of crustaceans, are what made a study like this possible in the first place," says Dr. Joel W. Martin, NHM Curator of Crustacea and one of the authors who designed the study nearly eight years ago. "The wealth of stored biodiversity information contained in it, both in terms of specimens and in terms of the data, theories, and research related to those specimens, are why natural history museums exist, and why they play such a critical role in explaining the world's diversity. Studies like this confirm the incredible value, not only of existing natural history museum collections, but of continuing to add to these collections every year."

A key problem that the research team had to solve was obtaining specimens of some of rare and obscure organisms whose DNA was needed for the analysis. Because of their extensive experience in field biology, this was a major contribution to the project from NHM scientists. Dr. Wetzer recalls lying on the beach with a microscope at Woods Hole, Massachusetts. She was hunting for specimens of a tiny, little-known crustacean that lives between grains of sand. "I got the mystacocarids we needed, but I think I also provided pretty good entertainment to the families at the beach that day," Dr. Wetzer said.

http://www.sciencedaily.com/releases/2010/02/100216114034.htm

(Submitted by Ray D)

Giant prawn was king of the early seas

http://metro.co.uk

Decline of Shorebird Linked to Bait Use of Horseshoe Crabs

Released: 2/12/2009 4:38:47 PM

Declining numbers of a shorebird called the red knot have been linked to bait use of horseshoe crabs.

Long-term surveys of red knots showed that the average weight of red knots when they leave Delaware Bay has declined significantly since their primary food source, eggs of horseshoe crabs, has been reduced. The study also revealed that red knot survivorship is related to departure weight, and that the population size of red knots has declined by more than 75 percent.

"We concluded that the increased harvest of horseshoe crabs led to a reduction in the food supply for red knots at a critical period in their annual cycle, and this led to a dramatic decline in population size," said USGS scientist, Jon Bart, one of the authors of the study.

There is a long tradition in Delaware Bay of harvesting horseshoe crabs for use as bait in various fisheries. In the years from 1992 to 1997, reported harvest of crabs grew 20 fold from about 100,000 individuals harvested to more than 2 million. This newly released study shows that this increase in horseshoe crab harvest has led to a dramatic decrease in the number of spawning crabs and to a 90 percent decline in crab eggs available for shorebirds to eat.

Delaware Bay is globally recognized as an important feeding stopover for migrating shorebirds, especially red knots. Each year, red knots migrate from Arctic breeding grounds to the southern tip of South America and back, covering more than 18,600 miles. In May, large numbers of red knots congregate in the bay during their northward migration where they gorge on horseshoe crab eggs in preparation for their continued migration to the Arctic.

Concern over red knot populations led to restrictions in horseshoe crab harvest starting in 1997. But as Lawrence Niles, a biologist with the Conserve Wildlife Foundation of New Jersey and senior author of the new study says, "Despite restrictions, the 2007 horseshoe crab harvest was still well above that of 1990, and no recovery of knots was detectable. Recovery of both horseshoe crabs and red knots may require more restrictions on horseshoe crab harvest, possibly even a complete moratorium for some period. We've proposed a program of adaptive management, including monitoring, that should result in the information managers need to find the right balance."

Fifteen scientists participated in the study, from a wide variety of federal, state, and nongovernmental entities. The results are published in the February edition of the science journal Bioscience. The title of the article is, "Effects of horseshoe crab harvest in Delaware Bay on red knots: Are harvest restrictions working?"

http://www.usgs.gov/newsroom/article.asp?ID=2137&from=rss_home