Sphaerius

Sphaerius is a genus of beetles in the family Sphaeriusidae, comprising 18 extant species. It is one of the two extant genera in the family, the other being Bezesporum. They are typically found along the edges of streams and rivers, where they feed on algae; they occur on all continents except Antarctica. Three species occur in the United States.

The overall form of the beetle is convex, glossy, dark brown or black with some markings possible. The head is prominent, with relatively large eyes set far apart, and capitate antennae. Total length ranges from Template:Cvt.

The beetles occur in a variety of damp environments, including mud, under stones, among plant roots and leaf litter, and in mosses in bogs. They store some air underneath their elytra.

Females produce a single large egg at a time.

The family used to be known as "Sphaeriidae", but the name was preoccupied by a family of freshwater clams. The name was inappropriately replaced with "Microsporidae" (by changing the genus name to Microsporus), but this act has been superseded by a return to the use of Sphaerius and a reformation of the family name as Sphaeriusidae.<ref>Template:Aut 2000: Opinion 1957. Sphaerius Waltl, 1838 (Insecta, Coleoptera): conserved; and Sphaeriidae Erichson, 1845 (Coleoptera): spelling emended to Sphaeriusidae, so removing the homonymy with Sphaeriidae Deshayes, 1854 (1820) (Mollusca, Bivalvia). Bulletin of zoological nomenclature, 57: 182–184. {{#if:0007-5167|Template:Catalog lookup link{{#if:Template:Trim|{{#ifeq:Template:Yesno-no|yes|Template:Main other|{{#invoke:check isxn|check_issn|Template:Trim|error=Template:Error-smallTemplate:Main other}}}}{{#if:Template:Trim|{{#ifeq:Template:Yesno-no|yes|Template:Main other|{{#invoke:check isxn|check_issn|Template:Trim|error=Template:Error-smallTemplate:Main other}}}}{{#if:Template:Trim|{{#ifeq:Template:Yesno-no|yes|Template:Main other|{{#invoke:check isxn|check_issn|Template:Trim|error=Template:Error-smallTemplate:Main other}}}}{{#if:Template:Trim|{{#ifeq:Template:Yesno-no|yes|Template:Main other|{{#invoke:check isxn|check_issn|Template:Trim|error=Template:Error-smallTemplate:Main other}}}}{{#if:Template:Trim|{{#ifeq:Template:Yesno-no|yes|Template:Main other|{{#invoke:check isxn|check_issn|Template:Trim|error=Template:Error-smallTemplate:Main other}}}}{{#if:Template:Trim|{{#ifeq:Template:Yesno-no|yes|Template:Main other|{{#invoke:check isxn|check_issn|Template:Trim|error=Template:Error-smallTemplate:Main other}}}}{{#if:Template:Trim|{{#ifeq:Template:Yesno-no|yes|Template:Main other|{{#invoke:check isxn|check_issn|Template:Trim|error=Template:Error-smallTemplate:Main other}}}}{{#if:Template:Trim|{{#ifeq:Template:Yesno-no|yes|Template:Main other|{{#invoke:check isxn|check_issn|Template:Trim|error=Template:Error-smallTemplate:Main other}}}}{{#if:Template:Trim|{{#ifeq:Template:Yesno-no|yes|Template:Main other|{{#invoke:check isxn|check_issn|Template:Trim|error=Template:Error-smallTemplate:Main other}}}}}}}}}}}}}}}}}}}}}}|Template:Error-small}} BioStor</ref> The position of the family within Coleoptera has also changed a number of times.<ref>Ross H. Arnett, Jr. and Michael C. Thomas, American Beetles (CRC Press, 2001)</ref>

Species

The genus includes the following 18 extant species, as of 2022:<ref name=":2">Template:Cite journal</ref>

• Sphaerius acaroides Template:Small – Europe
• Sphaerius africanus Template:Small – South Africa
• Sphaerius alticola Template:Small – Nepal
• Sphaerius coomani Template:Small – Vietnam
• Sphaerius gustavlohsei Template:Small – Nepal, India: Darjeeling
• Sphaerius hispanicus Template:Small – France, Spain, Algeria, Tunisia
• Sphaerius humicola Template:Small – Nepal
• Sphaerius laeviventris Template:Small – India: Uttarakhand
• Sphaerius madecassus Template:Small – Madagascar
• Sphaerius obsoletus Template:Small – Vietnam
• Sphaerius ovensensis Template:Small – Australia
• Sphaerius perlaevis Template:Small – Vietnam
• Sphaerius politus Template:Small – USA: California
• Sphaerius silvicola Template:Small – Nepal
• Sphaerius spississimus Template:Small – France: Corsica, Italy: Sardinia, Israel
• Sphaerius tesselatus Template:Small – Vietnam
• Sphaerius texanus Template:Small – USA: Texas
• Sphaerius tropicus Template:Small – Guatemala

Species transferred to Bezesporum:

• Sphaerius minutus Template:Small – China: Jiangxi
• Sphaerius papulosus Template:Small – Myanmar

Species of unclear assignment:

• Sphaerius cribratus Template:Small – Vietnam
• Sphaerius favosus Template:Small – Vietnam

Species excluded from Sphaeriusidae (actually representatives of Corylophidae):

• "Sphaerius" coenensis Template:Small – Australia
• "Sphaerius" scutellaris Template:Small – USA

Fossil species

• †Sphaerius martini Template:Small – Burmese amber, Myanmar, Cenomanian<ref>Template:Cite journal</ref>

External links

• Sphaeriusidae Tree of Life