Squalus acanthias (Spurdog):  

Predictions & Data for this entry

Model:  std  

MRE = 0.135
SMSE = 0.132

Zero-variate data
ab690 625.1 (0.09404)dage at birthJoneGeen1977
ap2190 2718 (0.2411)dage at pubertyAvsa2001
am2.92e+04 2.92e+04 (3.169e-05)dlife spanSteh2007
Lb 24 20.02 (0.1657)cmtotal length at birthJoneGeen1977
Lp 72 60.75 (0.1563)cmtotal length at pubertyAvsa2001
Li136 151.4 (0.1135)cmultimate total length (fem.)Avsa2001
Li_m121 122.7 (0.01416)cmultimate total length (males)Avsa2001
Ww0 35 37.94 (0.084)gwet weight at start (egg)YigiIsme2013
Wwp950 911.8 (0.04021)gwet weight at pubertyAvsa2001
Uni-variate data
DatasetFigure(RE)Independent variableDependent variableReference
LN see Fig. 1 (0.09723)total lengthmean numer of embryosAvsa2001
LW_m see Fig. 2 (0.1809)total lengthwet weightAvsa2001
LW_f see Fig. 2 (0.2132)total lengthwet weightAvsa2001
tLe see Fig. 3 (0.1512)ageembryo lengthJoneGeen1977
tYe see Fig. 4 (0.1848)ageyolk volumeJoneGeen1977
LW_m2 see Fig. 5 (0.1996)total lengthwet weightYigiIsme2013
LW_f2 see Fig. 5 (0.1289)total lengthwet weightYigiIsme2013
LW_e see Fig. 6 (0.2275)total lengthwet weightYigiIsme2013
Pseudo-data at Tref
DataGeneralised animalSqualus acanthiasUnitDescription
v 0.02 0.02774cm/denergy conductance
kap 0.8 0.8485-allocation fraction to soma
kap_R 0.95 0.95-reproduction efficiency
p_M 18 34.36J/d.cm^3vol-spec som maint
k_J 0.002 0.0021/dmaturity maint rate coefficient
kap_G 0.8 0.8027-growth efficiency


  • main food species: demersal fishes like: whiting (Merlangius merlangus euxinus), red mullet (Mullus barbatus) and black goby (Gobius niger) were the commonest. Also some common shrip Cragnon cragnon) (ref: Avsa2001)
  • Ovoviviparous. Depth around 50-149m, but have been found deeper than 700m. (ref: Wiki)
  • spurdogs favor a temp of 7 - 15 C (ref: Steh2007)


  • males are assumed to differ from females by {p_Am} only - we use the max. observed values of males and females from Avsa2001, not the von Bert paramter that they estimate.
  • predictions assume a mean temperature of 9 deg C
  • t-L data from YigiIsme2013 and Avsa2001 not included because after a lot of testing the age-length relationship is incoherent point to errors in the ageing, possible different type of error of the young ones with respect to the older ones. Possible different type of error between the studies. YigiIsme2016 age free swimming individuals of 17 cm to be ca 300 d old while length at birth is reported at 24-26 cm. These age estimates suggest a very high p_M while the rest of the data do not support this.
  • We use the actual length/ weight of smallest mature female in Avsa2001 and not the length where 50
  • Notice that egg weight is around 30 - 40 g (JoneGeen1977, YigiIsme2013) but that embryo weight around birth is > 50 g or more (YigiImse2013, fig. 6 of this AmP entry). This point to some external source of food from before birth. For this reason the slight discrepancy in predicted embryo length as function of time is acceptable.


  • The creation of this entry was supported by the Norwegian Science Council (NFR 255295)


  • Wiki
  • Kooy2010
  • Steh2007
  • Avsa2001
  • YigiIsme2016
  • YigiIsme2013
  • AnDiv
  • JoneGeen1977

Bibtex files with references for this entry

Bas Kooijman, 2013/03/08 (last modified by Starrlight Augustine 2017/03/13)

accepted: 2017/03/03

refer to this entry as: AmP Squalus acanthias version 2017/03/03 bio.vu.nl/thb/deb/deblab/add_my_pet/