You can sponsor this page

Probarbus jullieni Sauvage, 1880

Isok barb
Upload your photos and videos
Pictures | Google image
Image of Probarbus jullieni (Isok barb)
Probarbus jullieni
Picture by Freyhof, J.


Lao country information

Common names: Eun, Pa uhn, Pa eun
Occurrence: native
Salinity: freshwater
Abundance: scarce (very unlikely) | Ref: Davidson, A., 1975
Importance: highly commercial | Ref: Singhanouvong, D., C. Soulignavong, K. Vonghachak, B. Saadsy and T.J. Warren, 1996
Aquaculture: | Ref:
Regulations: protected | Ref:
Uses: no uses
Comments: Found mainly in the mainstream of large rivers. In the Mekong it is nearly restricted to the Mekong mainstream. Found below Mun-Chin River to the Khone Falls (Ref. 37772). Exclusive or nearly exclusive fishing for the species occurs only during the upstream reproductive migrations and actual spawning periods in the area near the Lee Pee Waterfalls in southern Laos. Farther upstream the fishery occurs at progressively later times. This important fisheries species is under serious longterm decline and this decline evidently is basinwide and the most obvious (but not necessarily only) reason is overfishing with gillnets during the reproductive migrations and spawning periods (Ref. 10431). Found mainly in deep slow reaches of the Mekong basin at Hee Village, Muang Mouan; undertakes upstream migration in November-January/February at Hee Village, Muang Mouan (Ref. 37769). Highly esteemed expensive food fish, locally consumed. Migrates upstream in October-December; according to Ban Hang Khone fishermen stock has declined 90% of 1970 level (Ref. 9497). Also undertakes downstream migration during the wet season in June-July through Hoo Som Yai at the Great Fault Line on the Mekong River, Champassack Province (Ref. 37771). One of the favorite food fish; meat is considered excellent; eggs are especially priced; made into "som kai pba eum", in which one part of fish eggs with salt and ground rice added is mixed with 15 parts of meat; the uncooked mix is placed in earthen jars to ferment for a number of days before eating (Ref. 12369). In the past, som kai pba eum was eaten mainly in the village where it was made, or occasionally sold at local festivals and celebrations (Ref. 12369). Catch, trade and transportation forbidden under the Fiat-Law on Fishery Management and Administration No. 33 KRO.CHOR of 19 March 1987, as "probatus jullieni". May be caught out of spawning season for local consumption, but cannot legally be caught during the spawning season or traded on a commercial basis at any time under the Lao Ministry of Agriculture and Forestry decree 118/MC 1989, updated 1991 (Ref. 12369). Becoming rare and locally extinct (Ref. 43281). Museum: Mekong at Ban Hang Khone, just below Khone falls, CAS 94159, 95476 (Ref. 5515). Also Ref. 2686, 4792, 7427, 12369, 30857, 36654, 37767, 37770, 44002, 56905.
National Checklist:
Country Information: https://www.cia.gov/library/publications/resources/the-world-factbook/geos/la.html
National Fisheries Authority:
Occurrences: Occurrences Point map
Main Ref: Roberts, T.R., 1993
National Database:

Common names from other countries

Classification / Names Common names | Synonyms | Catalog of Fishes(genus, species) | ITIS | CoL | WoRMS | Cloffa

Teleostei (teleosts) > Cypriniformes (Carps) > Cyprinidae (Minnows or carps) > Probarbinae
Etymology: Probarbus: Greek, pro = first, in front of + Latin, barbus = barbel (Ref. 45335).
  More on author: Sauvage.

Environment: milieu / climate zone / depth range / distribution range Ecology

Freshwater; brackish; demersal; potamodromous (Ref. 37770).   Tropical; 28°N - 5°N

Distribution Countries | FAO areas | Ecosystems | Occurrences | Point map | Introductions | Faunafri

Asia: Mekong, Chao Phraya and Meklong basins of Indo-China and Thailand, and the Pahang and Perak basins of Malaysia (Ref. 7427). Catch, trade and transportation forbidden in Laos (Ref. 12217).

Size / Weight / Age

Maturity: Lm ?  range ? - ? cm
Max length : 150 cm SL male/unsexed; (Ref. 30857); common length : 28.0 cm TL male/unsexed; (Ref. 2073); max. published weight: 70.0 kg (Ref. 12369)

Short description Morphology | Morphometrics

Dorsal soft rays (total): 13; Anal soft rays: 8. Differs from P. labeamajor in having only 5 (instead of 6) stripes between lateral line scale row and dorsal fin base; lips not enlarged, free posterior margin of lower lip interrupted at midline; large adults without mentum; maxillary barbel invariably well developed, length one-third or more of eye diameter. The only species in which body stripes may extend to every scale row, but this only occurs in some larger and more darkly pigmented individuals. P. labeamajor and P. labeaminor have no more than three stripes below lateral line scale row, and the abdomen is uniformly white. Adults and larger juveniles of P. jullieni usually have much more red and sometimes yellow coloration on head, body, and fins than the other two species. Scale rows between lateral line scale row and pelvic fin 4.

Biology     Glossary (e.g. epibenthic)

Inhabits mainly the mainstream of large rivers (Ref. 10431), with sand or gravel substrates and abundant mollusks populations (Ref. 12693). Occurs in deep slow reaches (Ref. 37769). Feeds on aquatic plants, insects and shelled mollusks. Spawns in winter (late December-early February) in big riverine deltas over sand and gravel substrate with water current of 1.3 m/sec (Ref. 6459). Undertakes spawning and trophic migrations in the Mekong basin. Trophic migrations occurs throughout its occurrence range which takes place mainly at the onset of the flood season and are mainly undertaken by juveniles and subadults (Ref. 37770). Upstream spawning migrations take place between October and February from Kompong Cham in Cambodia to Chiang Khong in Thailand. At Chiang Khong , fishermen reported that Probarbus moves up the tributary Nam Ta in Laos to breed in March-April. Three Probarbus species were also reported to migrate together, but spawn separately, in January-February at Sungkom, Nong Khai Province in Thailand (Ref. 37770). Egg is buoyant, yellow and 2 mm in diameter. Hatching occurs in 32 hrs at 23°C (Ref. 6459). An excellent foodfish, sometimes consumed raw, but rather scarce so it fetches a high market price (Ref. 2686). Eggs are especially priced (Ref. 12369). Used to be cultured commercially in Thailand (Ref. 7306). May be caught individually or in small numbers of any size incidentally with gillnetting and other fishing activities, at virtually any time or place in the Mekong mainstream (Ref. 10431), but mostly caught during November-January spawning migration, when it is by far the most important species in fisheries catch (Ref. 12369). In the Mekong this important fisheries species is under serious long-term decline and this decline evidently is basin wide and the most obvious (but not necessarily only) reason is overfishing with gillnets during the reproductive migrations and spawning periods (Ref. 10431). Attains 70 kg or more, but mostly marketed size nowadays are 5-20 kg (Ref. 12369).

Life cycle and mating behavior Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae

Main reference Upload your references | References | Coordinator | Collaborators

Roberts, T.R., 1992. Revision of the Southeast Asian cyprinid fish genus Probarbus, with two new species threatened by proposed construction of dams on the Mekong River. Ichthyol. Explor. Freshwat. 3(1):37-48. (Ref. 7427)

IUCN Red List Status (Ref. 130435)

  Critically Endangered (CR) (A2d); Date assessed: 29 January 2019

CITES (Ref. 128078)


CMS (Ref. 116361)

Not Evaluated

Threat to humans

  Harmless




Human uses

Fisheries: commercial; aquaculture: experimental; gamefish: yes
FAO(Aquaculture: production; ; publication : search) | FishSource |

More information

Countries
FAO areas
Ecosystems
Occurrences
Introductions
Stocks
Ecology
Diet
Food items
Food consumption
Ration
Common names
Synonyms
Metabolism
Predators
Ecotoxicology
Reproduction
Maturity
Spawning
Fecundity
Eggs
Egg development
Age/Size
Growth
Length-weight
Length-length
Length-frequencies
Morphometrics
Morphology
Larvae
Larval dynamics
Recruitment
Abundance
References
Aquaculture
Aquaculture profile
Strains
Genetics
Electrophoreses
Heritability
Diseases
Processing
Mass conversion
Collaborators
Pictures
Stamps, Coins Misc.
Sounds
Ciguatera
Speed
Swim. type
Gill area
Otoliths
Brains
Vision

Tools

Special reports

Download XML

Internet sources

Estimates based on models

Phylogenetic diversity index (Ref. 82804):  PD50 = 0.6250   [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00447 (0.00173 - 0.01152), b=3.12 (2.89 - 3.35), in cm Total Length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245).
Trophic level (Ref. 69278):  3.2   ±0.40 se; based on food items.
Resilience (Ref. 120179):  Very Low, minimum population doubling time more than 14 years (Preliminary K or Fecundity.).
Fishing Vulnerability (Ref. 59153):  Very high vulnerability (90 of 100).
Price category (Ref. 80766):   Unknown.