C. Barnes, D. M. Bethea, R. D. Brodeur, J. Spitz, V. Ridoux, C. Pusineri, B. C. Chase, M. E. Hunsicker, F. Juanes, A. Kellermann, J. Lancaster, F. Ménard, F.-X. Bard, P. Munk, J. K. Pinnegar, F. S. Scharf, R. A. Rountree, K. I. Stergiou, C. Sassa, A. Sabates, and S. Jennings. 2008. Predator and prey body sizes in marine food webs. Ecology 89:881.

METADATA CLASS I. DATA SET DESCRIPTORS

A. Data set identity: Marine predator and prey sizes with corresponding environmental data.

B. Data set identification code

Suggested Data Set Identity Code: Predator_and_prey_body_sizes_in_marine_food_webs_vsn3.txt

C. Data set description: 34931 records from 27 marine locations providing global coverage and a wide range of environmental conditions for a range of predator sizes from 0.1 mg to over 415 kg and prey sizes from 75 pg to over 4.5 kg. Types of predators and the study locations are listed in Table 1 and the scope of the data set, with predator and prey size expressed as mass, is shown in Fig. 1.

Version 3 (new version posted on 11 April 2008) – updated to:

a) correct predator mass, corrupted in version2

a) increase significant figures from 3 to 5 in all floating point fields

b) correct 14 records that had corrupted prey lengths (record numbers: 28041, 28042, 29091, 29101, 29108,29109,28133, 29303, 29724, 29989, 30081, 30082, 30086, 30087)

c) correct 8 records where the "Prey quality of conversion to length" field was set incorrectly (record numbers: 6639, 6746, 6747, 6748, 6750, 6751, 6890, 7240)

d) correct 19 records that had incorrect (duplicate) values in "Individual ID" (record numbers: 18855, 18857, 18858, 18860, 18862, 18865, 18866, 18867, 18869, 18871, 18872, 18873, 18876, 18878, 18879, 18880, 18883, 18884, 18885).

TABLE 1. Predator types and location details for predator and prey mass data by data source.

FIG. 1. Relationship between the body mass of predators and their prey. 99.4% of points fall below the 1:1 line.

Principal Investigator: Carolyn Barnes, Centre for Environment, Fisheries and Aquaculture Science, Lowestoft, Suffolk, NR33 0HT, UK. (Carolyn.Barnes@cefas.co.uk).

Abstract:

Knowledge of relationships between predator and prey size are needed to describe interactions of species and size classes in food webs. Most estimates of predator and prey sizes have been based on dietary studies and apply to small numbers of species in a relatively narrow size range. These estimates may or may not be representative of values for other groups of species and body sizes or for other locations. Marine predator and prey size data associated with published literature were identified and collated to produce a single data set. If predator or prey length or mass were not measured in the original study, the length or mass was calculated using length–mass relationships. The data set consists of 34931 records from 27 locations covering a wide range of environmental conditions from the tropics to the poles and for 93 types of predator with sizes ranging from 0.1 mg to over 415 kg and 174 prey types with sizes from 75 pg to over 4.5 kg. Each record includes: predator and prey scientific names, common names, taxa, life stages and sizes (length and mass with conversion details), plus the type of feeding interaction, geographic location (with habitat description, latitude, longitude) and mean annual environmental data (sea surface temperature and primary productivity).

D. Key words: body size; consumer resource; energy transfer; food web; marine; transfer efficiency.

CLASS II. RESEARCH ORIGIN DESCRIPTORS

A. Overall project description

Identity: Relationship between predator and prey sizes in the marine environment.

Originators: Simon Jennings, Centre for Environment, Fisheries and Aquaculture Science, Lowestoft, Suffolk, NR33 0HT, UK.

Period of Study: November 2006 – ongoing

Objectives: To enhance the understanding of predator–prey size relationships and any effect of variable environmental factors.

Source(s) of funding: Defra contract/grant number: MF1001

CLASS III. DATA SET STATUS AND ACCESSIBILITY

A. Status

Latest Update: Vsn 3 April 2008

Latest Archive date:

Metadata status: The metadata are complete and up to date.

Data verification: Data quality has been carefully checked as described in classV, section B, below.

B.Accessibility

Storage location and medium:Copies of the latest version of the data file are being stored on the principal investigator’s personal computer and the Cefas network in Microsoft Excel and Text format.

Contact person:

Carolyn Barnes, Centre for Environment, Fisheries and Aquaculture Science, Lowestoft, Suffolk, NR33 0HT, UK.

Phone: +44 1502 562244, Fax: +44 1502 513865

E-mail: Carolyn.Barnes@cefas.co.uk

Copyright restrictions: None.

Proprietary restrictions: None.

Costs: None.

CLASS IV. DATA STRUCTURAL DESCRIPTORS

A. Data Set File

Identity:Predator_and_prey_body_sizes_in_marine_food webs_vsn3.txt

Size: 34931 records, not including header row.

Format and Storage mode: ASCII text, tab delimited. Winzip (Nico Mak Computing, Inc., Mansfield, CT 06268 USA) compression was used.

Header information: Headers describe the content of each column. See section B below for detailed descriptions of the column contents .

Alphanumeric attributes: Mixed.

Special characters/fields: If no information is available for a given record, this is indicated by 0.00E+00 in numeric fields and "n/a" in character fields.

Authentication procedures: The sums of the numeric columns are:

Record number: 610,104,846, Individual ID: 257,871,362, Predator length: 14,381,399, Predator standard length: 9,623,154, Predator fork length: 8,653,798, Predator total length: 14,279,735, Standardised predator length: 2,380,360, Predator quality of length-mass conversion: 39,463, Predator mass: 128,950,109, Predator mass check: 1,998,658,943, Predator mass check diff: 1,869,707,163, Predator ratio mass/mass: 480,471, SI predator mass: 128,950,109, Prey length: 2,536,593, Prey quality of conversion to length: 11,963, SI prey length: 283,924, Prey width: 256,585, Prey mass: 992,386, Prey mass check: 9,245,038, Prey mass check diff: 8,252,729, Prey ratio mass/mass: 300,779, SI prey mass: 992,297, Prey quality of conversion to mass: 113,730, Depth: 54,555,460, Mean annual temp: 529,768, SD annual temp: 152,519; Mean PP: 25,400,155, SD PP: 2,418,130

B. Variable information

Variable name	Variable definition	Units	Storage type	Range numeric values	Missing value codes
Record Number	Record number	N/A	Integer	1–34931	N/A
In-ref ID	Predator ID in original work	N/A	Character	N/A	"n/a"
Individual ID	Individual predator ID	N/A	Integer	1–17668	"n/a"
Predator	Scientific species name of predator (Genus species)	N/A	Character	N/A	N/A
Predator common name	Common name of predator	N/A	Character	N/A	N/A
Predator  taxon	Ectotherm vertebrate or cephalopod	N/A	Character	N/A	N/A
Predator lifestage	Larva, postlarva, juvenile or adult	N/A	Character	N/A	N/A
Type of feeding interaction	Insectivorous, piscivorous, planktivorous, or predacious	N/A	Character	N/A	N/A
Predator length	Predator length (as in original work if available, else regressed from mass)	Defined in next column "Predator length unit"	Floating point	3–17490	N/A
Predator length unit	μm, mm or cm	N/A	Character	N/A	N/A
Predator dimension measured	Predator dimension/s measured	N/A	Character	N/A	N/A
Predator standard length	Standard length of predator (if applicable)	Defined in "Predator length unit"	Floating point	0–17490	0.00E+00
Predator fork length	Fork length of predator (if applicable)	Defined in "Predator length unit"	Floating point	0–19104	0.00E+00
Predator total length	Total length of predator (if applicable)	Defined in "Predator length unit"	Floating point	0–22423	0.00E+00
Predator TL/FL/SL conversion reference	Reference for conversion between length dimensions	N/A	Character	N/A	N/A
Standardised predator length	TL where available else SL or FL	cm	Floating point	0.3–309.69	N/A
Predator measurement type	Individual, mean or mid-class	N/A	Character	N/A	N/A
Predator length-mass conversion method	Regression equation for length–mass conversion	N/A	Character	N/A	"n/a"
Predator length-mass conversion reference	Reference for regression equation for length–mass conversion	N/A	Character	N/A	"n/a"
Predator quality of length-mass conversion	0 = mass measured, 1 = species regression, 2 = genus regression, 3 = family regression, 4 = general shape, 5 = unsatisfactory	N/A	Integer	0–4	N/A
Predator mass	Mass of predator	Defined in next column "Predator mass unit"	Floating point	0.000171–380050	N/A
Predator mass unit	g	N/A	Character	N/A	N/A
Predator mass check	Calculated mass of sphere with diameter = "Standardised predator length". Assumes 1 mL = 1 g	g	Floating point	0.00141–1554400	N/A
Predator mass check diff	Calculated mass of sphere with diameter = "Standardised predator length" – SI predator mass	g	Floating point	0.0012–1289400	N/A
Predator ratio mass/mass	Calculated mass of sphere with diameter = "Standardised predator length" / SI predator mass	g	Floating point	3.8–16.8	N/A
SI predator mass	Predator mass (measured or calculated from length–mass regression)	g	Floating point	0.000171–380050	N/A
Diet coverage	Types of prey items included in original work ("all" or the type of prey if the study was selective).	N/A	Character	N/A	N/A
Prey	Scientific species name of prey (Genus species) where specified in original work	N/A	Character	N/A	N/A
Prey common name	Common name of prey	N/A	Character	N/A	N/A
Prey taxon	Ectotherm invertebrate, ectotherm vertebrate, egg, microzooplankton or mixed	N/A	Character	N/A	N/A
Prey length	Prey length (as in original work if available, else regressed from mass)	Defined in next column "Prey length unit"	Floating point	0.08–17976	N/A
Prey length unit	μm, mm, or cm	N/A	Character	N/A	N/A
Prey conversion to length method	Regression equation for mass–length conversion	N/A	Character	N/A	"n/a"
Prey quality of conversion to length	0 = length measured, 1 = species regression, 2 = genus regression, 3 = family regression, 4 = general shape, 5 = unsatisfactory	N/A	Integer	0–4	N/A
Prey conversion to length reference	Reference for regression equation for length–mass conversion	N/A	Character	N/A	"n/a"
SI prey length	Prey length (measured or calculated from mass–length regression)	cm	Floating point	0.000416–122.66	N/A
Prey dimension measured	Prey dimension/s measured	N/A	Character	N/A	N/A
Prey width	Prey width if measured	Defined in next column "Prey width unit"	Floating point	0.4534–1950	"n/a"
Prey width unit	μm or mm	N/A	Character	N/A	"n/a"
Prey measurement type	Individual, mean mid-range or preferred	N/A	Character	N/A	N/A
Prey mass	Mass of prey	Defined in next column "Prey mass unit"	Floating point	7.53 × 10-11–4587	N/A
Prey mass unit	mg or g	N/A	Character	N/A	N/A
Prey mass check	Calculated mass of sphere with diameter = "SI prey length". Assumes 1 mL = 1 g	g	Floating point	3.77 × 10-12–96571	N/A
Prey mass check diff	Calculated mass of sphere with diameter = "SI prey length" – SI prey mass (g)	g	Floating point	-115.1–96135	N/A
Prey ratio mass/mass	Calculated mass of sphere with diameter = "SI prey length" / SI prey mass (g)	g	Floating point	0.019–846.7	N/A
SI prey mass	Prey mass (measured or calculated from length–mass regression)	g	Floating point	7.53 × 10-11–4587	N/A
Prey conversion to mass method	Regression equation for length–mass conversion or "weighed"	N/A	Character	N/A	"n/a"
Prey conversion to mass reference	Reference for regression equation for length–mass conversion	N/A	Character	N/A	"n/a"
Prey quality of conversion to mass	0 = mass measured, 1 = species regression, 2 = genus regression, 3 = family regression, 4 = general shape, 5 = unsatisfactory	N/A	Integer	0–5	N/A
Geographic location	Location of study in original work	N/A	Character	N/A	N/A
Latitude	Latitude of study in original work (taken directly from the relevant publication or determined from charts and descriptions)	N/A	Character	N/A	N/A
Longitude	Longitude of study in original work (taken directly from the relevant publication or determined from charts and descriptions)	N/A	Character	N/A	N/A
Depth	Estimated depth using the General Bathymetric Chart of the Oceans (GEBCO) digital atlas (maintained and published by the British Oceanography Data Centre, Proudman Oceanographic Laboratory, Bidson Observatory, Birkenhead, Merseyside, L43 7RA).	m	Integer	5–4785	N/A
Mean annual temp	Estimates of mean annual sea surface temperature (SST) derived from the Moderate-Resolution Imaging Spectroradiometer (MODIS) aboard the NASA terra-satellites.	ºC	Floating point	-1.3–29	N/A
SD annual temp	1 standard deviation of mean in previous column	ºC	Floating point	0.6–6.6	N/A
Mean PP	Estimated primary production obtained for the years 2001 to 2004 at a 36 × 36 km resolution from the outputs of a model that uses the approach of Longhurst et al. 1995 to predict primary production from the surface concentration of chlorophyll a pigment as measured by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS)Mélin, 2003.	mg C·m-2·d-1	Integer	91–1739	N/A
SD PP	1 standard deviation of mean in previous column	mg C·m-2·d-1	Integer	7–214	N/A
Reference	Reference of original work	N/A	Character	N/A	N/A
Specific habitat	Description of location of study in original work	N/A	Character	N/A	N/A
Notes / assumptions	Comments	N/A	Character	N/A	N/A

 

CLASS V. SUPPLEMENTAL DESCRIPTORS

A. Data acquisition

The published literature was searched for relevant research (Barraclough, 1967; Bainbridge and McKay, 1968; Kellermann, 1986, 1987, 1989, 1990; Lancaster, 1991; Stergiou and Fourtouni, 1991; Munk, 1992; Juanes and Conover, 1995; Munk, 1997; Brodeur, 1998; Sabates and Saiz, 2000; Scharf et al., 2000; Chase, 2002; Pinnegar et al., 2003; Bethea et al., 2004; Quero et al., 2004; Sassa and Kawaguchi, 2004; Ostergaard et al., 2005; Pusineri et al., 2005; Bethea et al., 2006; Chancollon et al., 2006; Hunsicker and Essington, 2006; Ménard et al., 2006). The corresponding author was contacted and asked for permission for their data to be included and if given, a request for the raw data was made. In two cases the authors could not be contacted due to the age of the publication and copyright permission was acquired from the relevant body (Barraclough, 1967; Bainbridge and McKay, 1968).

B. Quality assurance/quality control procedures

Where possible the data was electronically copied. In other cases it was manually input. Once reformatted the data was sent back to the original authors for their approval.

The conversion between length and mass for all predators and prey were coded by the specificity of the regression equation used (0 = dimension measured, 1 = species regression, 2 = genus regression, 3 = family regression, 4 = general shape, 5 = unsatisfactory). The results were checked by calculating the mass of a sphere with diameter equal to the length and comparing this to the result of the conversion. For all predators the mass was less than for a sphere. For 1853 of the 34931 prey the mass was greater than for a sphere. Of these, 43 had been actually weighed so it is their length measurements that are suspect, 6 were converted using a family level regression and the other 1804 were converted using a "general shape" regression. The check data is included in the dataset so any user can exclude records or ideally recommend modifications to the conversion equations if more reliable versions are known to be available.

C. Related material: Two tables, one showing predator length–mass conversion and the other showing prey length–mass conversion, displayed below.

Supplementary Table 1: Predator length–mass conversion equations and references. Length values used in regression equations are SL = standard length, TL = total length, FL = fork length, ML = mantle length.

Latin name (as given in data reference)	Common name	Predator length to weight conversion method	Units	Level of mass conversion	Predator length–mass conversion primary reference	Predator length–mass conversion reference cited by
Acanthocepola sp.	surgeon / tang / unicorn	M=0.0201SL^1.9637	cm, g	Family	Froese and Pauly 2007	Fishbase (family)
Ammodytes hexapterus	Pacific sandlance	M=0.0021SL^3.1525	cm, g	Genus	Froese and Pauly 2007	Fishbase (genus)
Anarhichas lupus	Atlantic wolf fish	M=0.0033SL^3.2491	cm, g	Species	Coull et al. 1989
Anarhichas minor	Spotted wolf fish	M=0.0017SL^3.399	cm, g	Species	Nikolsky 1957	Fishbase (species)
Arnoglossus imperialis	iImperial scaldfish	M=0.0045TL^3.170	cm, g	Species	Pereda and Villamor 1991	Fishbase (species)
Aspitrigla cuculus	red gurnard	M=0.0056SL^3.1688	cm, g	Species	Dorel 1986
Benthosema glaciale	Myctophidae fish larva	M=0.105SL^2.8904	cm, g	Family	Froese and Pauly 2007	Fishbase (family)
Carangoides sp.	jack / pompano	M=0.0269SL^2.8891	cm, g	Family	Froese and Pauly 2007	Fishbase (family)
Carcharhinus brevipinna	spinner shark	M=0.0075TL^2.970	cm, g	Species	Branstetter 1987	Fishbase (species)
Carcharhinus isodon	finetooth shark	M=0.0058SL^3.1151	cm, g	Genus	Froese and Pauly 2007	Fishbase (genus)
Carcharhinus limbatus	blacktip shark	M=0.0061TL^3.0100	cm, g	Species	García-Arteaga et al. 1997	Fishbase (species)
Ceratoscopelus maderensis	Myctophidae fish larva	M=0.0105SL^2.8904	cm, g	Family	Froese and Pauly 2007	Fishbase (family)
Chionodraco rastrospinosus	icefish	M=0.0006SL^3.6225	cm, g	Family	Froese and Pauly 2007	Fishbase (family)
Clupea harengus	Atlantic herring	M=0.0050SL^3.1915	cm, g	Species	Coull et al. 1989
Clupea pallasii	Pacific herring	M=0.0045FL^3.1270	cm, g	Species	Bond and Erickson 1993
Cynoglossus sp.	tonguefish	M=0.0030SL^3.1188	cm, g	Genus	Froese and Pauly 2007	Fishbase (genus)
Cynoscion regalis	weakfish	M=0.0088TL^3.0	cm, g	Species	Crozier and Hecht 1913	Fishbase (species)
Diaphus garmani	Myctophidae fish larva	M=0.0059TL^3.060	cm, g	Species	Madureira and Rossi-Wongtschowski 2005	Fishbase (species)
Dicentrarchus labrax	European sea bass	M=0.0123TL^2.9554	cm, g	Species	Dorel 1986
Eutrigla gurnardus	grey gurnard	M=0.0075SL^3.0287	cm, g	Species	CEFAS Endeavour cruise 07/05	Unpublished
Gadus morhua	Atlantic cod	M=0.0070SL^3.0870	cm, g	Species	Bedford et al. 1986
Galeorhinus galeus	tope	M=0.0061TL^2.9400	cm, g	Species	Annala 1994	Fishbase (species)
Gasterosteus aculeatus	threespine stickleback	M=0.0113SL^3.0000	cm, g	Species	Pauly et al. 1998	Fishbase (species)
Gilbertidia sigalutes	soft sculpin	M=0.0231FL^3.0000	cm, g	Family	Froese and Pauly 2007	Fishbase (family)
Hemilepidotus hemilepidotus	red Irish lord	M=0.0282TL^3.0000	cm, g	Species	Crawford 1993	Fishbase (species)
Hemilepidotus spinosus	brown Irish lord	M=0.0771SL^2.6036	cm, g	Genus	Froese and Pauly 2007	Fishbase (genus)
Hemitripterus americanus	sea raven	M=0.0183FL^3.0000	cm, g	Species	Froese and Pauly 2007	Fishbase (species)
Hexagrammos decagrammus	kelp greenling	M=0.0156TL^3.0000	cm, g	Species	Crawford 1993	Fishbase (species)
Hygophum benoiti	Myctophidae fish larva	M=0.105SL^2.8904	cm, g	Family	Froese and Pauly 2007	Fishbase (family)
Hypomesus pretiosus	surf smelt	M=0.0110SL^2.8799	cm, g	Family	Froese and Pauly 2007	Fishbase (family)
Lampanyctus crocodilus	Myctophidae fish larva	M=0.0051TL^2.9800	cm, g	Species	Merella et al. 1997	Fishbase (species)
Lepidorhombus boscii	4-spot megrim	M=0.0037TL^3.245	cm, g	Species	Papaconstantinou et al. 1993	Fishbase (species)
Lepidorhombus whiffiagonis	megrim	M=0.0033SL^3.2237	cm, g	Species	Dorel 1986
Leucoraja fullonica	shagreen ray	M=0.0047SL^3.1417	cm, g	Genus	Froese and Pauly 2007	Fishbase (genus)
Loligo pealeii	longfin squid	M=0.0004L^2.4124	mm, g	Species	Personal communication (Mary Hunsicker)
Lophius americanus	goosefish	M=0.0170SL^3.0010	cm, g	Species	Armstrong et al. 1992	Fishbase (species)
Lophius budegassa	black-bellied angler	M=0.0130SL^3.0010	cm, g	Species	Tsimenides and Ondrias 1980	Fishbase (species)
Lophius piscatorius	monkfish	M=0.0255SL^2.8458	cm, g	Species	Dorel 1986
Lumpenella longirostris	longsnout prickleback	M=0.0016FL^3.0000	cm, g	General shape	Froese and Pauly 2007	Fishbase (eel-like)
Lumpenus sagitta	snake prickleback	M=0.0016FL^3.0000	cm, g	General shape	Froese and Pauly 2007	Fishbase (eel-like)
Melanogrammus aeglefinus	haddock	M=0.0062SL^3.1150	cm, g	Species	Bedford et al. 1986
Merlangius merlangus	whiting	M=0.0062SL^3.1029	cm, g	Species	Dorel 1986
Merluccius bilinearis	silver hake	M=0.0039SL^3.16	cm, g	Species	Schaefer 1960	Fishbase (species)
Merluccius merluccius	hake	M=0.0097SL^2.9130	cm, g	Species	Bedford et al. 1986
Merluccius productus	Pacific hake	M=0.0204FL^2.695	cm, g	Species	Dark 1975	Fishbase (species)
Micromesistius poutassou	blue whiting	M=0.0038SL^3.0820	cm, g	Species	Dorel 1986
Molva molva	ling	M=0.0041SL^3.0700	cm, g	Species	Bedford et al. 1986
Mustelus canis	smooth dogfish	M=0.0023TL^3.1	cm, g	Species	van der Elst 1981	Fishbase (species)
Myctophum asperum	Myctophidae fish larva	M=0.0206SL^2.6286	cm, g	Genus	Froese and Pauly 2007	Fishbase (genus)
Myctophum punctatum	Myctophidae fish larva	M=0.015SL^3.0000	cm, g	Species	Pauly et al. 1998	Fishbase (species)
Myoxocephalus octodecimspinosus	longhorn sculpin	M=0.0116SL^3.1122	cm, g	Genus	Froese and Pauly 2007	Fishbase (genus)
Notolepis rissoi	Paralepididae fish larva	M=0.0019SL^2.946	cm, g	Family	Froese and Pauly 2007	Fishbase (family)
Nototheniops larseni	Antarctic fish	M=0.0159SL^3.0000	cm, g	Genus	Froese and Pauly 2007	Fishbase (genus)
Oncorhynchus gorbuscha	pink salmon	M=0.0034SL^3.3000	cm, g	Species	Erokhin 1990	Fishbase (species)
Oncorhynchus keta	chum salmon	M=0.023FL^3.2	cm, g	Species	Ricker 1964	Fishbase (species)
Oncorhynchus nerka	sockeye salmon	M=0.0192TL^3.0000	cm, g	Species	Crawford 1993	Fishbase (species)
Ophiodon elongatus	lingcod	M=0.0133TL^3.0000	cm, g	Species	Crawford 1993	Fishbase (species)
Paralichthys dentatus	summer flounder	M=0.0054SL^3.117	cm, g	Species	Henderson 1979	Fishbase (species)
Paralichthys oblongus	fourspot flounder	M=0.0075TL^3.1272	cm, g	Family	Froese and Pauly 2007	Fishbase (family)
Pleuragramma antarcticum	Antarctic Silverfish	M=0.0045SL^3.25	cm, g	Species	Kunzmann 1986	Fishbase (species)
Pollachius pollachius	pollack	M=0.0061TL^3.1153	cm, g	Species	Dorel 1986
Pollachius virens	saithe	M=0.0103SL^2.9630	cm, g	Species	Bedford et al. 1986
Pomatomus saltatrix	bluefish	M=0.0136TL^2.899	cm, g	Species	Haimovici and Velasco 2000	Fishbase (species)
Psychrolutes paradoxus	tadpole sculpin	M=0.0231FL^3.0000	cm, g	Family	Froese and Pauly 2007	Fishbase (family)
Raja clavata	thornback ray	M=0.0032SL^3.1938	cm, g	Species	Dorel 1986
Raja erinacea	little skate	M=0.0027SL^3.184	cm, g	Species	Waring 1984	Fishbase (species)
Raja montagui	spotted ray	M=0.0099TL^3.2051	cm, g	Species	Coull et al. 1989
Raja naevus	cuckoo ray	M=0.0387TL^2.9591	cm, g