Lyrosoma

Mannerheim, 1853

Species Guides

1

Lyrosoma is a of primitive carrion beetles in the Agyrtidae, comprising at least three described . Members are small beetles associated with coastal marine environments across the northern Pacific Rim, from Korea and Japan through Russia to Alaska and the Aleutian Islands. The genus represents one of the few carrion beetle lineages specialized for coastal necromass-based .

Lyrosoma opacum (4433477124) by D. Sikes from Fairbanks, USA. Used under a CC BY-SA 2.0 license.Lyrosoma opacum Jacobson by Georgiy Jacobson. Used under a Public domain license.Breeding Lyrosoma opacum on bird carcass (4433477856) by D. Sikes from Fairbanks, USA. Used under a CC BY-SA 2.0 license.

Pronunciation

How to pronounce Lyrosoma: /laɪˈroʊsəmə/

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Identification

Distinguished from other Agyrtidae by combination of small body size (approximately 4-5 mm), coastal association, and specific morphological characters including presence or absence of epistomal and elytral reticulation patterns. Lyrosoma pallidum and L. opacum are separable by body size differences and elytral surface . Both occur sympatrically on Kamchatka and several Kurile Islands.

Images

Habitat

Strictly coastal: found under stones, in rock crevices above high tide, on sandy beaches, and among seaweed wrack along seashores. Also recorded from nests of maritime birds including peregrine falcon nests with prey carcasses. include rocky shores, back beaches, beach caves, and seawalls.

Distribution

Northern Pacific coastal regions. L. pallidum: Korea (Gangwon Province), Japan (Hokkaido, Honshu), Russia (Kamchatka Peninsula, Kurile Islands, Sakhalin, Magadan). L. opacum: Russia (Kurile Islands from Urup northward, Kamchatka, Commander Islands), United States (Aleutian Islands, Pribilof Islands, Kodiak Island, Afognak Island, Chirikof Island).

Host Associations

  • crested auklet carcass - carcass associationcollection record
  • Peregrine falcon nest - nest substrate with prey carcassescollection record
  • bird carcass - carcass associationgeneral collection record
  • fish carcass - carcass associationcollection record
  • decaying seaweeds/starfish - substrate associationcollection record from kelp wrack

Life Cycle

stages and detailed developmental unknown.

Behavior

Active in intertidal and supratidal zones. Collected via pitfall trapping and hand collection from under rocks, kelp wrack, and in cracks of back beach rocks. Occurs in beach caves and above beach zones.

Ecological Role

Associated with carrion and decaying marine organic matter in coastal . Part of shift from plant-based to necromass-based energy flow on volcanic islands.

Similar Taxa

  • other AgyrtidaeLyrosoma are distinguished by strict coastal marine specialization; most other Agyrtidae occur in terrestrial forest or cave environments.

More Details

Sympatry

L. pallidum and L. opacum are sympatric on Kamchatka Peninsula and several Kurile Islands (Ketoi, Cirpoi, Yanchika), representing the only documented localities where both co-occur.

Sources and further reading