Literature based dataset of body length-weight relationships
Length-weight relationships offer a convenient means of estimating individual body mass from simple measurements of individual length. This dataset provides an extensive collection of length-weight relationships compiled from the literature for over 7,500 animal species, primarily invertebrates and fish. At higher taxonomic levels, the dataset covers 162 animal orders, of which 152 are currently accepted, accounting for more than 15% of all recognised animal orders. The ones corresponding to historical or deprecated orders are indicated in the dataset with an asterisk (*).
Default
About this resource
- Alternate Identifier
-
a4dfdffb-0d0e-42da-88e9-166ed9778ba7
- Publication Date
- 2026-09-02
- Title
-
Literature based dataset of body length-weight relationships
- Abstract
-
Length-weight relationships offer a convenient means of estimating individual body mass from simple measurements of individual length. This dataset provides an extensive collection of length-weight relationships compiled from the literature for over 7,500 animal species, primarily invertebrates and fish. At higher taxonomic levels, the dataset covers 162 animal orders, of which 152 are currently accepted, accounting for more than 15% of all recognised animal orders. The ones corresponding to historical or deprecated orders are indicated in the dataset with an asterisk (*).
- Dataset Language
-
English
- Dataset Creator
- Dataset Creator
- Metadata Provider
- Metadata Provider
- Associated Party
- Associated Party
- Dataset Contact
- Dataset Contact
- Keywords (Environmental Thesaurus)
-
-
Animals
-
- Keywords (Traits Thesaurus)
-
-
Body length
-
Body weight
-
Allometric scaling
-
Geographic Coverage
- Geographic Description
-
Global dataset
Bounding Box
- West Bounding Coordinate
-
-176.19
- East Bounding Coordinate
-
175.30
- North Bounding Coordinate
-
78.95
- South Bounding Coordinate
-
-68.55
Temporal Coverage
Range of Dates
- Begin Date
-
1991-01-01
- End Date
-
2024-01-01
License Information
- Intellectual Rights
-
Free for use, including sharing and adaptation, by all individuals provided that the owners are acknowledged in any use or publication.
Distribution
Online
- A brief description of the the content of online URL.
-
Info and download page on LifeWatch Italy Data Portal
Methods
• Method
Method Step
- Description
-
This dataset was compiled from existing data available in international repositories and peer-reviewed literature, selecting records containing length-weight regressions at the taxonomic levels of species, genus, family, and order. Length-weight relationships are expressed using the allometric equation: W=aL^b, where W is body weight, L is body length, a is the allometric coefficient, and b is the allometric exponent. Length-weight relationships originally reported in logarithmic form were transformed into the above equation to ensure consistency across data sources. The dataset was subsequently harmonised using controlled vocabularies.
qualityControl
- Description
-
Taxonomic validation was conducted using the ChecklistBank tool available through Catalogue of Life to verify the validity of taxonomic names. Geographical data were reviewed and transformed into decimal degree coordinates where necessary to ensure data interoperability and reusability. Where possible, missing information from the original datasets was reconstructed and added to the final dataset.
Data Tables
• Data Table
- Name
-
Database_body_length-weight_relationships.csv
Physical
- Object Name
-
Database_body_length-weight_relationships.csv
- Size
-
42122167
- Authentication
-
MD5:91536c5be9577dc3563406165fe460b0
- Character Encoding
-
UTF-8
Data Format
- textFormat
-
1
column
;
Attribute List
Attribute
- Name
-
catalogNumber
- Label
-
Catalog Number
- Definition
-
An identifier (preferably unique) for the record within the data set or collection.
Measurement Scale
nominal
nonNumericDomain
textDomain
- Definition
-
Any Text
Attribute
- Name
-
continent
- Label
-
Continent
- Definition
-
The name of the continent in which the location occurs.
Measurement Scale
nominal
nonNumericDomain
textDomain
- Definition
-
Any Text
Attribute
- Name
-
country
- Label
-
Country
- Definition
-
The name of the country or major administrative unit in which the location occurs.
Measurement Scale
nominal
nonNumericDomain
textDomain
- Definition
-
Any Text
Attribute
- Name
-
locality
- Label
-
Locality
- Definition
-
The specific description of the place. This term may contain information modified from the original to correct perceived errors or standardize the description.
Measurement Scale
nominal
nonNumericDomain
textDomain
- Definition
-
Any Text
Attribute
- Name
-
decimalLatitude
- Label
-
Decimal Latitude
- Definition
-
The geographic latitude of the geographic center of a Location (in decimal degrees, using the spatial reference system WGS84). Positive values are north of the Equator, negative values are south of it. Legal values lie between -90 and 90, inclusive.
Measurement Scale
Ratio
Unit
- standardUnit
-
degree
Numeric domain
- Number type
-
real
Attribute
- Name
-
decimalLongitude
- Label
-
Decimal Longitude
- Definition
-
The geographic longitude of the geographic center of a Location (in decimal degrees, using the spatial reference system WGS84). Positive values are east of the Prime Meridian, and negative values are west of it. Legal values lie between -180 and 180, inclusive.
Measurement Scale
Ratio
Unit
- standardUnit
-
degree
Numeric domain
- Number type
-
real
Attribute
- Name
-
eventDate
- Label
-
Event Date
- Definition
-
The date-time or interval during which an Event occurred. For occurrences, this is the date-time when the event was recorded.
Measurement Scale
Date time
- Format String
-
YYYY-MM-DD
Attribute
- Name
-
scientificName
- Label
-
Scientific Name
- Definition
-
The scientificname, with authorship and date information if known, as it originally appeared before of the taxonomic check.
Measurement Scale
nominal
nonNumericDomain
textDomain
- Definition
-
Any Text
Attribute
- Name
-
acceptedNameUsage
- Label
-
Accepted Name Usage
- Definition
-
The full scientific name, with authorship and date information if known. When forming part of an Identification, this should be the name in lowest level taxonomic rank that can be determined. This term should not contain identification qualifications, which should instead be supplied in the IdentificationQualifier term.
Measurement Scale
nominal
nonNumericDomain
textDomain
- Definition
-
Any Text
Attribute
- Name
-
acceptedNameUsageID
- Label
-
Accepted Name Usage ID
- Definition
-
An identifier for the name usage (documented meaning of the name according to a source) of the currently valid (zoological) or accepted (botanical) taxon.
Measurement Scale
nominal
nonNumericDomain
textDomain
- Definition
-
Any Text
Attribute
- Name
-
scientificNameAuthorship
- Label
-
Scientific Name Authorship
- Definition
-
The authorship information for the scientificName formatted according to the conventions of the applicable nomenclaturalCode.
Measurement Scale
nominal
nonNumericDomain
textDomain
- Definition
-
Any Text
Attribute
- Name
-
kingdom
- Label
-
Kingdom
- Definition
-
The full scientific name of the kingdom in which the taxon is classified.
Measurement Scale
nominal
nonNumericDomain
textDomain
- Definition
-
Any Text
Attribute
- Name
-
phylum
- Label
-
Phylum
- Definition
-
The full scientific name of the phylum or division in which the taxon is classified.
Measurement Scale
nominal
nonNumericDomain
textDomain
- Definition
-
Any Text
Attribute
- Name
-
class
- Label
-
Class
- Definition
-
The full scientific name of the class in which the taxon is classified.
Measurement Scale
nominal
nonNumericDomain
textDomain
- Definition
-
Any Text
Attribute
- Name
-
order
- Label
-
Order
- Definition
-
The full scientific name of the order in which the taxon is classified. An asterisk (*) indicates historical or deprecated taxonomic orders that are no longer considered valid in current classifications but were retained to preserve consistency with the original data source.
Measurement Scale
nominal
nonNumericDomain
textDomain
- Definition
-
Any Text
Attribute
- Name
-
family
- Label
-
Family
- Definition
-
The full scientific name of the family in which the taxon is classified.
Measurement Scale
nominal
nonNumericDomain
textDomain
- Definition
-
Any Text
Attribute
- Name
-
genus
- Label
-
Genus
- Definition
-
The full scientific name of the genus in which the taxon is classified.
Measurement Scale
nominal
nonNumericDomain
textDomain
- Definition
-
Any Text
Attribute
- Name
-
taxonRank
- Label
-
Taxon Rank
- Definition
-
The taxonomic rank of the most specific name in the scientificName.
Measurement Scale
nominal
nonNumericDomain
textDomain
- Definition
-
Any Text
Attribute
- Name
-
a
- Label
-
a
- Definition
-
Allometric coefficient of the length-weight relationship M=aL^b. It corresponds to the antilogarithm of the intercept of the linearized regression.
Measurement Scale
Ratio
Unit
- Custom Unit
-
g/cm
Numeric domain
- Number type
-
real
Attribute
- Name
-
b
- Label
-
b
- Definition
-
Allometric exponent of the length–weight relationship M=aL^b. It corresponds to the slope of the linearized regression.
Measurement Scale
Ratio
Unit
- standardUnit
-
dimensionless
Numeric domain
- Number type
-
real
Attribute
- Name
-
r2
- Label
-
R-squared
- Definition
-
R-squared represents the proportion of variance in the dependent variable that can be predicted from the independent variables.
Measurement Scale
Ratio
Unit
- standardUnit
-
dimensionless
Numeric domain
- Number type
-
real
Attribute
- Name
-
bodyWeight
- Label
-
Body Weight
- Definition
-
Any measurable characteristic related to the body weight of an organism.
Measurement Scale
ordinal
nonNumericDomain
enumeratedDomain
- codeDefinition
-
Ash free dry weight
The weight of organic material obtained as difference between the dry weight and the ash weight
- codeDefinition
-
Dry weight
The weight of an organism after removal of body fluids drying at 50-70 °C (typically at 60 °C) in a drying oven for 24 hours or until constant weight is reached.
- codeDefinition
-
Wet weight
The weight of a whole fresh organism.
Attribute
- Name
-
bodySize
- Label
-
Body Size
- Definition
-
Morphological measurable characteristic related to the size of the body or part of the body of an organism. Body size is comparable across taxa and variable through time and space. Body size can vary within taxonomic groups, with gender and life stage.
Measurement Scale
ordinal
nonNumericDomain
enumeratedDomain
- codeDefinition
-
Body length
The total distance from point to point along the longest axis of the body of an organism.
- codeDefinition
-
Shell length
The maximum linear distance of the shell of an organism; measured along its longest axis.
- codeDefinition
-
Head length
The linear distance corresponding to the length of the head.
- codeDefinition
-
First pereonite length
The linear distance between the anterior and posterior margins of the first pereonite (first thoracic segment); measured along the longitudinal body axis.
- codeDefinition
-
Cephalothorax length
The linear measurement of the cephalothorax; the body region formed by the fusion of the head and thorax.
- codeDefinition
-
Pleotelson length
The linear distance from the anterior boundary of the pleotelson to its posterior distal tip.
- codeDefinition
-
Body width
The total distance from side to side of the body of an organism; measured perpendicular to its longest axis at the widest point.
- codeDefinition
-
6th chaetiger width
The linear distance corresponding to the width of the sixth chaetiger; measured perpendicular to the longitudinal body axis.
- codeDefinition
-
10th chaetiger width
The linear distance corresponding to the width of the tenth chaetiger; measured perpendicular to the longitudinal body axis.
- codeDefinition
-
Mandible length
The linear distance between the proximal articulation point and the distal tip of the mandible.
- codeDefinition
-
Chaetigers width
The width measurement of the portion of the body that contains the chaetigerous segments.
- codeDefinition
-
Standard length
Length of a fish measured from the tip of the snout to the posterior end of the last vertebra or to the posterior end of the midlateral portion of the hypural plate.
- codeDefinition
-
Fork length
Length of a fish from the tip of the snout to the end of the middle caudal fin rays.
- codeDefinition
-
Disk width
The greatest distance between the lateral tips of the pectoral fins in Rajiformes.
- codeDefinition
-
Thorax width
The linear distance corresponding to the width of the thorax; typically measured across its widest point in dorsal view.
- codeDefinition
-
Chela width
The linear distance corresponding to the width of the chela; typically measured across its widest point.
- codeDefinition
-
Carapace width
The maximum linear distance measured across the carapace at its widest point; perpendicular to its longest axis.
- codeDefinition
-
Carapace length
The linear distance measured from the anterior to the posterior edge of the carapace along its longest axis.
- codeDefinition
-
Capitulum length
The linear distance corresponding to the length of the capitulum.
- codeDefinition
-
Arm length
The maximum linear distance of an arm; measured from its proximal to its distal end along its longitudinal axis.
- codeDefinition
-
Central disk diameter
The maximum linear distance measured across the central body disk through its centre; excluding the arms.
- codeDefinition
-
Mantle length
The linear distance corresponding to the length of the mantle.
- codeDefinition
-
Shell width
The maximum linear distance of the shell of an organism; measured perpendicular to its longest axis at the widest point.
- codeDefinition
-
Head width
The linear distance corresponding to the width of the head.
- codeDefinition
-
Abdominal length
For arthropods (when the abdomen is clearly distinguishable); distance measured in dorsal view from its most anterior part to its posterior ending.
Attribute
- Name
-
minimumBodyLength
- Label
-
Minimum Body Length
- Definition
-
The minimum value in a range of body length values.
Measurement Scale
Ratio
Unit
- standardUnit
-
centimeter
Numeric domain
- Number type
-
real
Attribute
- Name
-
maximumBodyLength
- Label
-
Maximum Body Length
- Definition
-
The maximum value in a range of body length values.
Measurement Scale
Ratio
Unit
- standardUnit
-
centimeter
Numeric domain
- Number type
-
real
Attribute
- Name
-
organismQuantity
- Label
-
Organism Quantity
- Definition
-
A number or enumeration value for the quantity of organisms.
Measurement Scale
Ratio
Unit
- standardUnit
-
number
Numeric domain
- Number type
-
real
Attribute
- Name
-
habitat
- Label
-
Habitat
- Definition
-
A category or description of the habitat in which the event occurred.
Measurement Scale
ordinal
nonNumericDomain
enumeratedDomain
- codeDefinition
-
Freshwater
Habitat characterised by water with low salinity; such as rivers ponds and lakes.
- codeDefinition
-
Marine
Saltwater environment.
- codeDefinition
-
Transitional water
Transitional coastal areas where freshwater from the land and saltwater from the sea mix
-
Attribute
- Name
-
lifeStage
- Label
-
Life Stage
- Definition
-
An age class or life stage of a organism.
Measurement Scale
ordinal
nonNumericDomain
enumeratedDomain
- codeDefinition
-
Adult
An organism that is fully grown or sexually mature.
- codeDefinition
-
Juvenile
An organism that is not fully grown or sexually mature.
- codeDefinition
-
Larval stage
A distinct juvenile form many animals undergo before metamorphosis into adults.
Attribute
- Name
-
associatedReferences
- Label
-
Associated References
- Definition
-
A list (concatenated and separated) of identifiers (publication, bibliographic reference, global unique identifier, URI) of literature associated with the occurrence.
Measurement Scale
nominal
nonNumericDomain
textDomain
- Definition
-
Any Text
- numberOfRecords
-
98468
