Skip to main content

CO1 barcode analysis and extensive SEM data revisit the old world Micropholcus spiders

CO1 barcode analysis and extensive SEM data revisit the old world Micropholcus spiders

NEWS - Micropholcus Deeleman-Reinhold & Prinsen, 1987, is one of only two genera of Pholcidae known in both the Old and New Worlds. However, there are large morphological and ecological differences among geographically separated species groups and molecular data to unite all these species into a single genus.

The researchers reviewed and redescribed the Old World Micropholcus from four previously known species and twelve new species from Saudi Arabia (M. dhahran, M. harajah, M. alfara, M. abha, M. tanomah, M. bashayer, M. maysaan), Oman (M. darbat, M. shaat), Morocco (M. ghar, M. khenifra), and the Philippines (M. bukidnon).

Bernhard Huber and Guanliang Meng from the Zoological Research Museum Alexander Koenig in Bonn, conducted analyses based on CO1 barcodes, extensive SEM data, and first records of Acroceridae (Diptera) larvae in Pholcidae, extracted from book lungs. The interspecific distance had an average value of 19.8% (3.4–25.7%). Only seven of the 371 distance values were at or below 10%. All of these referred to species in the Saudi Arabian group.

In the northern Saudi Arabian group, the distance between M. maysaan and the other two species (M. tanomah, M. bashayer) ranged from 8.0–10.0%. The distance between M. tanomah and M. bashayer was 10.2%. Despite these low values, the two best-scoring partitions in the ASAP analysis separated these three species.

In the southern Saudi Arabian group, M. alfara and M. dhahran were very close (3.4%); the distances of these two species to M. harajah were only 6.1–6.7%. Most partitions in the ASAP analysis separated M. alfara and M. dhahran as a single species and only the best (and worst) separated M. harajah as a distinct species.

From a morphological perspective, there were consistent differences among specimens for the different nominal species. These differences are at about the same level of uniqueness as among relatives in many genera of Pholcidae. Furthermore, the traits of each are remarkably homogeneous.

However, from a molecular perspective, they suggest distinct species boundaries, particularly among the southern Saudi Arabian group. The genetic distance of 3.4–6.7% is clearly below the problematic range of overlap between intra- and interspecific distances for Pholcidae.

The ASAP analysis suggests that this group contains only one or two species, not three. The researchers give more weight to the morphological evidence. Almost every location in the highlands with suitable habitat in Saudi Arabia has its own Micropholcus ‘species’ and it is expected that the extent to Yemen will dramatically increase the number of species.

Micropholcus in the Old World has a wide geographic range but appears to be largely restricted to semiarid regions, where the spiders lead a solitary life in caves, in cave-like chambers under rocks, and in rock depressions.

The Arabian Peninsula and Morocco are particularly species-rich, suggesting that this genus must also be present in suitable habitats across a large but under-sampled area, including M. bukidnon. The Philippines extends the distribution of the genus far eastward, but the species are morphologically exceptional and rely only on molecular evidence.

Micropholcus is highly diverse in southwestern Saudi Arabia as one of the richest biodiversity regions in the Arabian Peninsula and high species richness is also found in Yemen. The Saudi Arabian species appear to be restricted to the highlands (above 1200 m). The Yemeni species are often morphologically distinct but genetically very close.

Acroceridae flies primarily attack cursorial and fossorial spider species, probably due to the larval strategy for locating spider hosts. Researchers have documented the first case of Acroceridae larvae developing in the book lungs of web-building Pholcidae. Acroceridae larvae spend the day at the top of the dome-shaped web that is firmly attached to a rock surface.

Original research

Huber BA, Meng G (2024). Old World Micropholcus spiders, with first records of acrocerid parasitoids in Pholcidae (Araneae). ZooKeys 1213: 95-182, DOI:10.3897/zookeys.1213.133178

Dlium theDlium

Popular Posts

Korean mulberry (Morus indica)

Murbei or Korean mulberry ( Morus indica ) is a species of plant in Moraceae, shrub or small tree, up to 10 meters tall, slow growing, cylindrical stem, light brown with white nodules, M. indica has heart-shaped or oval-shaped leaves and sometimes three-lobed, 4-12.5 cm long, 2.5-7.5 cm wide, pointed tip, serrated margin, green and has a stalk. Monoecious inflorescences with male and female grow on the same tree, though often on different branches. Male flowers have a size of 9-11.5 mm and are covered with fine hairs. The female flowers are subglubose or only round in shape, measuring 6-9.5 mm. Stigma is 3.5 mm long with short, thick hair. The female flowers form compound fruit and are fleshy, green and white-haired to white, red and black when ripe. Korean mulberry is used in regulating blood glucose levels in diabetic patients. Kingdom: Plantae Phylum: Tracheophyta Subphylum: Angiospermae Class: Magnoliopsida Order: Rosales Family: Moraceae Genus: Morus Species: Morus indica

Broad-handed carpenter bee (Xylocopa latipes)

Broad-handed carpenter bee ( Xylocopa latipes ) is an animal species in the Apidae, tropical wood bees, very large, strong, solitary lives and builds nests by burrowing into fallen trees to telephone poles in forests and cities with warm tropical climates. X. latipes is overall black and shiny with black wings that turn bluish or greenish or metallic purple in sunlight. A pair of large eyes and a pair of antennae have broad bases. The back has a horizontal line. The abdomen is oval in shape with segments, the margins are wide and the back has thick hair. The broad-handed carpenter bee produces a loud, distinctive low-pitched hum that can be heard in flight. Kingdom: Animalia Phylum: Arthropoda Subphylum: Hexapoda Class: Insecta Subclass: Pterygota Order: Hymenoptera Suborder: Apocrita Infraorder: Aculeata Superfamily: Apoidea Epifamily: Anthophila Family: Apidae Subfamily: Xylocopinae Tribe: Xylocopini Genus: Xylocopa Subgenus: Platynopoda Species: Xylocopa latipes

Malabar melastome (Melastoma malabathricum)

Senggani or malabar melastome ( Melastoma malabathricum ) is a plant species in Melastomataceae, shrubs, 0.5-5 m tall, woody stems, sympodial branches and reddish brown, scaly young branches or tightly haired, taproots and brown, widely used for materials ink and medicine. M. malabathricum has single and stemmed leaves, oval, 2-20 cm long, 1-8 cm wide, tapered, flat edges, rough and hairy surface, upper surface dark green and bright green underside. A straight bone in the middle and two curved bones on the edge. Malabar melastome blooms throughout the year, compound, clustered at the tips of branches and light purple, 3-4 cm in diameter, sticky petals, hair, short end, tapered tip, scaly protective leaves and reddish purple. The flower has 8-12 stamens, 3 cm long, pink, a pistil, potted green potted head and ovaries have 4-6 spaces. Five crowns, ovoid and bright purple. The fruit has a rough skin, dark red and has many black seeds with aryl, cup-shaped and 8 mm long. Ripe fru...