Halacarellus schefferi


Scientific Name: Halacarellus schefferi

Phylum: Arthropoda

Class: Arachnida

Order: Trombidiformes

Family: Halacaridae

Genus: Halacarellus


schefferi [Describe here as A. iricolor]

Native Distribution

Origin Realm:


Native Region:

Origin Location:

Arctic Bering sea (holotype from 57º05'N, 170º25'W) (Newell 1951) *Holotype RELATED: Temperate Northern Pacific [Hallacarellus spp.] Black Sea, French Atlantic coast, North Sea, Baltic (Bartsch 2004) STATUS NOT STATED Western Indo-Pacific [Halacarellus spp.] Indian Ocean (Bartsch 1997) STATUS NOT STATED [family Halacaridae] Tropical eastern Indian Ocean (Bartsch 2002) STATUS NOT STATED Temperate Northern Atlantic [family Halacaridae] Temperate northeastern Atlantic, Mediterranean/Black Sea/Aral Sea (Bartsch 2002) STATUS NOT STATED Tropical Atlantic [family Halacaridae] Tropical eastern Atlantic (Bartsch 2002) STATUS NOT STATED Southern Ocean [Halacarellus obsoletus and Halacarellus thomasi] Antarctica (Bartsch 1995) STATUS NOT STATED Uncertain realm [Halacarellus spp.] cosmopolitan genus (Newell 1951) STATUS NOT STATED [Halacarellus spp.] North Atlantic, North Pacific, South Atlantic, South Pacific (Bartsch 1997) STATUS NOT STATED [Hallacarellus spp.] Eastern and western north Atlantic (Bartsch 2004) STATUS NOT STATED [family Halacaridae] tropical western Pacific, temperate southeastern Pacific, temperate southeastern Atlantic (Bartsch 2002) STATUS NOT STATED

Geographic Range:

Species only specifically noted in the Bering Sea (Newell 1951)

General Diversity:


Non-native Distribution

Invasion History:

No records of invasion (Global Invasive Species Database 2015)

Non-native Region:

Not applicable

Invasion Propens:

Not applicable

Status Date Non-native:

Not applicable

Vectors and Spread

Initial Vector:

See details

Second Vector:

see details

Vector Details:

RELATED: [family Halacaridae] Possible vectors include rafting (e.g., on drift algae); shallow water species may be transported by storms, water fowl, insects; bathyal and deep-sea species may be transported by sediment moved by underwater "storms", currents, debris, and macrofauna (Bartsch 2002)

Spread Rate:

Not applicable

Date First Observed in Japan:

Not applicable

Date First Observed on West coast North America:

Not applicable


Impact in Japan:

Not applicable

Global Impact:

Not applicable


Native Temperature Regime:

See details

Native Temperature Range:

RELATED: [Halacarellus spp.] cold temperate and polar water (Bartsch 1997); one species in tropical Caribbean waters (Bartsch 1984, cited in Bartsch 1997) [Halacarellus spp.] Present in the shallow waters (0-200m) of northern polar, northern temperate, tropical, southern temperate, and southern polar seas (Bartsch 2002)

Non-native Temperature Regime:

Not applicable

Non-native Temperature Range:

Not applicable

Native Salinity Regime:

See details

Native Salinity Range:

RELATED: [Halacarellus spp.] several species are found in brackish water, some in freshwater (Bartsch 1997, Bartsch 2002). [Halacarellus spp.] 48 marine species in the genus (Bartsch 2002) [Halacarellus spp.] most are marine (Tuzovsky 2010) [Halacarellus kamchatkaensis] freshwater (Tuzovsky 2010) [family Halacaridae] Black Sea: 18-22 psu (Walter & Proctor 2013)

Non-native Salinity Regime:

Not applicable

Temperature Regime Survival:


Temperature Range Survival:


Temperature Regime Reproduction:


Temperature Range Reproduction:


Salinity Regime Survival:


Salinity Range Survival:


Salintiy Regime Reproduction:

Polyhaline, Euhaline

Salinity Range Reproduction:


Depth Regime:

Lower intertidal, Shallow subtidal, See details

Depth Range:

[Aleutians (Alaska, USA)] very common in intertidal and shallow-dredged collections; both intertidal and subtidal; holotype from lower intertidal zone (Newell 1951) RELATED: [Halacarellus spp.] 0 ->1000 m (Bartsch 2002) [Halacarellus spp.] Observed in both shallow waters and deep sea regions (Bartsch 2006) [Halacarellus obsoletus] Found from 185m (shallowest depth sampled) to 275m depth within the tissue of hexactinellid sponges in Antarctica (Bartsch 1995)

Non-native Salinity Range:

Native Abundance:



Fertilization Mode:


Reproduction Mode:

Gonochoristic/ dioecious

Spawning Type:

Not applicable

Development Mode:

Benthic larva

Asexual Reproduction:

Parthenogenesis/ Agamospermy (Parthenogenesis is the development of an unfertilized egg in animals. Agamospermy is the production of fertile seeds without pollination in plants)

Reproduction Details:

Separate sexes with ovipositor and penis (Newell 1951) RELATED: [Subclass Acari] sperm is transferred from male to female; when penis is present, transfer is via copulation (Kozloff 1990) [Halacarellus spp.] one larval and two known nymphal stages (Bartsch 1997, Bartsch 2006) [Family Halacaridae] Little is known about sperm transfer; free-standing stalked spermatophores have been described for several species (Pepato & da Rocha 2010, cited in Walter & Proctor 2013). [Superfamily Halacaroidea] Copulation has evolved repeatedly (Walter & Proctor 2013) [Family Halacaridae] Parthenogenesis is known from one species in the family (Bartsch 2002, 2006) [Family Halacaridae] generally oviparous; separate sexes; univoltine life cycle with either short or prolonged periods of reproduction; low fecundity (Bartsch 2006) [Family Halacaridae] females stick the eggs firmly to the substratum (Bartsch 2006)

Adult Mobility:

Actively mobile (Mobility is a normal part of at least part of the adult life cycle - at least in spurts. Not dependent upon distance traveled)

Adult Mobility Details:

RELATED: [Family Halacaridae] crawl amongst the substratum (Bartsch 2015)

Maturity Size:


Maturity Age:


Reproduction Lifespan:



VARIABILITY RELATED: [family Halacaridae] Some of the warm-temperate and tropical species have a one year life span (Bartsch 1992b, cited in Bartsch 2002, Bartsch 1996b, cited in Bartsch 2002) [Family Halacaridae] Adults live five to nine months (Bartsch 2006)

Broods per Year:

RELATED: [family Halacaridae] one generation per year, or two eggs at a time (Bartsch 2002)

Reproduction Cues:

RELATED: [Family Halacaridae] Temperature and day length influence reproductive cycle (Bartsch 2006)

Reproduction Time:



RELATED: [family Halacaridae] usually fewer than 20 eggs per female per lifetime (Bartsch 2002) [Family Halacaridae] Low fecundity (Bartsch 2006) [Family Halacaridae] A female usually contains 10-20 eggs at the same time (which are deposited in groups); psammophilous genera bear a single large (elaborately textured) egg, with possibly one or two small one (Bartsch 2006)

Egg Size:


Egg Duration:


Early Life Growth Rate:

RELATED: [Family Halacaridae] Larval phase lasts a few days; nymphal stages last a few weeks or several months (Bartsch 2006)

Adult Growth Rate:


Population Growth Rate:


Population Variablity:




Rocky intertidal, Rocky subtidal, See details

Habitat Type:

See details


See details


See details

Habitat Expansion:


Habitat Details:

[Aleutians (Alaska, USA)] Both intertidal and subtidal; holotype from lower intertidal zone; found on rocks, "etc." (Newell 1951) RELATED: [Halacarellus spp.] Found in interstitial-rich sand, amongst debris in sediments and burrows of macrofauna (as endo- and epifauna), on algal turf and fronds, amongst colonial organisms (e.g., bryozoans), and associated with macrofauna (e.g., sponges) (Bartsch 2002) [Halacarellus spp.] Found amongst coralline algae, algae, gravel, barnacles, mussels (Carlton 2007) [Halacarellus spp.] Various species found amongst barnacles and Lichina; green, red, and brown algae in pools and on open rock; on sublittoral material; in crevices and under stones; habitat use varied greatly between species (Pugh & King 1985) [Halacarellus spp.] Found in coarse sandy deposits just above the water line; interstitially between sand particles; both above and below the waterline (Bartsch 2004) [Halacarellus obsoletus and Halacarellus thomasi] Found within the tissue of hexactinellid sponges in Antarctica (Bartsch 1995) [Halacarellus spp.] Live in small crevices, microcavernes, on epiflora and fauna, on surface structures or gill chambers of macrofauna, in the interstitia amongst sandy deposits and flocculent debris. Not found in silt or in long-term hypoxic areas. Usually free-living (Bartsch 2015)

Trophic Level:


Trophic Details:

RELATED: [Halacarellus spp.] most are carnivorous, but may at times be algivorous (Bartsch 1997) [Subclass Acari] marine mites are primarily predators and feed on crustaceans and worms (Kozloff 1990) [superfamily Halacaroidea] Eat just about anything; range from fungivores to predators to parasites (Walter & Proctor 2013) [Family Halacaridae] Observed eating protozoans, oligochaetes and other small metazoans, copepods; some species (not listed) act as parasites to larger invertebrates (Walter & Proctor 2013) [Family Halacaridae]Feed on tissue of macrofaunal species, on meiofauna, protozoans, fungi, bacteria (Bartsch 2006)

Forage Mode:


Forage Details:

RELATED: [Halacarellus spp.] most are carnivorous, but may at times be algivorous (Bartsch 1997, 2006)

Natural Control:

RELATED: PREDATION [Family Halacaridae] [Predation] populations are reduced by predators, such as carnivorous invertebrates, other halacarids, and small fishes (Bartsch 2006) [Superfamily Halacaroidea] [Predation] seldom eaten; much less than expected by their abundance. Likely due to bright colouration and bad taste. Also difficult to digest (Walter & Proctor 2013) PARASITES [Halacarellus spp.] [Parasites or hitchhikers] known to bear suctorians (Bartsch 2015) [Family Halacaridae] [Parasites or hitchhikers] May be infested by epizoa (suctorians, peritrich ciliates) and epiphyta (unicellular green algae, diatoms). Endoparasites are not known (Bartsch 2006) DISTURBANCE [Family Halacaridae] [Disturbance] populations are reduced by destruction of their substratum or physical or chemical disturbance (Bartsch 2006)

Associated Species:

RELATED: PARASITES [Halacarellus spp.] [Parasites or hitchhikers] known to bear suctorians (Bartsch 2015) [Family Halacaridae] [Parasites or hitchhikers] May be infested by epizoa (suctorians, peritrich ciliates) and epiphyta (unicellular green algae, diatoms). Endoparasites are not known (Bartsch 2006)

References and Notes


Bartsch I (2008) Halacarellus obsoletus n. sp. (Arachnida: Acari: Halacaridae), an Associate with Antarctic Hexactinellid Sponges. Mitteilungen aus dem Museum für Naturkunde in Berlin. Zoologisches Museum und Institut für Spezielle Zoologie (Berlin) 71: 121-128. onlinelibrary.wiley.com/doi/10.1002/mmnz.19950710113/abstract Bartsch I (1997) Thalassarachna and Halacarellus (Halacaridae: Acari): two separate genera. Journal of Natural History 31: 1223-1236. www.tandfonline.com/doi/abs/10.1080/00222939700770661 Bartsch I (2002) Geographical and ecological distribution of marine halacarid genera and species (Acari: Halacaridae). Experimental & Applied Acarology 34: 37-58. link.springer.com/article/10.1023/B:APPA.0000044438.32992.35 Bartsch I (2004) The Black Sea halacarid fauna (Halacaridae, Acari): faunal comparison with the Mediterranean, Eastern North Atlantic, North Sea, and Baltic and reflection on its origin. Zoosystematics and Evolution 80: 143-158. onlinelibrary.wiley.com/store/10.1002/mmnz.20040800202/asset/20040800202_ftp.pdf Bartsch I (2006) Halacaroidea (Acari): a guide to marine genera. Organisms Diversity & Evolution 6, Electronic supplement 6: 1-104. www.senckenbergmuseum.de/odes/06-06.pdf Bartsch I (2015) Halacaridae (Acari) amongst the epiflora and fauna on trunks, branches, roots, and pneumatophores on the coast of Singapore: A survey. Raffles Bulletin of Zoology 31: 96-138. https://lkcnhm.nus.edu.sg/nus/images/data/raffles_bulletin_of_zoology/supplement31/S31rbz096-138.pdf Carlton JT (2007) The Light and Smith manual: intertidal invertebrates from central California to Oregon. London, England: University of California Press, Ltd Global Invasive Species Database. http://www.issg.org/database/species/search.asp?sts=sss&st=sss&fr=1&x=22&y=15&sn=Halacarellus+schefferi&rn=&hci=-1&ei=-1&lang=EN Access date: 05-08-2015 Kozloff EN (1990) Invertebrates. Philadelphia, PA: Saunders College Publishing Newell IM (1951) New species of Agaue and Thalassarachna from the Aleutians (Acari, Halacaridae). American Museum Novitates 1489: 1-19. digitallibrary.amnh.org/handle/2246/3983 Pugh PJA & King PE (1985) Vertical distribution and substrate association of the British Halacaridae. Journal of Natural History 19: 961-968. www.tandfonline.com/doi/abs/10.1080/00222938500770601 Tuzovsky PV (2010) DESCRIPTION OF A NEW WATER MITE SPECIES OF THE GENUS HALACARELLUS K. VIETS (ACARI: HALACARIDAE) FROM KAMCHATKA. Acarina 18: 67-72. insects.ummz.lsa.umich.edu/acarina/PDFS/2010_1/Tuzovsky2010.pdf Walter DE & Proctor HC (2013) Acari Underwater, or, Why Did Mites Take the Plunge? In Mites: Ecology, Evolution & Behaviour. Retrieved from link.springer.com/chapter/10.1007/978-94-007-7164-2_7


Little or no information; expert opinion based on general knowledge


• Newell 1951 uses old name for this species • Only species-level information used for multi-selects; higher level info used for drop downs • Many possibly useful papers not available; some useful papers in German