ininor piwt, of t h tottrl lipid illl(l triglyccrides were t h c b niitjor class of
lipid in many cwpcpods iiiliubiting thv upper 325 tn, whereas the wax
esters w(!rv i he tniLin lipid constitileiit, arid triglycerides were a ininor
lipid cwniponrnt for till c.oppods esainined from depths below 625 m.
The 326-fJdh ni tlepth intcrvd t~ppeurcd to be a transition zone. A
Hitnilar tcwclcwcy was oh-rvetl by Morris (1 972) in the analysis of
lipid of ot Iicr oc(~i~tlic crustiLwirnH including a few shrimps taken from
differcwt depths in the North Atlantic and western Mediterranean.
According to him, wax chstcrs were present us only a sinall fraction
( .
:
.
20% t otcrl lipid) in t h species tnigrating in t,he upper 600-700 m
(Acnntiqhyra purpurea mid Systelluspz’s deehilis) or living on the seafloor (Ilefr~rocnvpus erhsifw A . Milnc Edwitrds and H. grimnldii A. Milne
Etlwixrils et Uoiivier). Convc~~e’ly, Acanthephyra pelayicn living below
WO n i coi1tiiid :L much higher percentage of wax esters (44-65%
total lipid).
Wax estcrs and tryglyc*critles have different densities and comprcssibilities reliLtive t o thittj of‘ seawater. According to Alexander
(2!)72) the ncritrnl huoyimvy of fish for which volurne/mass = 50
cni3kg-1 run he achieved i).\r means of wax esters if they constitute
about 20% of tho t o t d body weight. Some of the deep-living pelagic
shrimp, whose volnme/mass is near to 50 cm3kg-l, appear to have
wax esters very close to this aniount. Accumulation of wax esters by
~ n c ~ ~ p ~ l i k g i c
m d 1)ntliyycliigio shritnps is accepted as an evolutionary
aclirptation in conncxion wit ti vertical migr2Ltion and buoyancy regulation, rillied to soin(* fitctors such iLK t~hc reduction in cixrltpace calcification. l)cntjou r’f al. (unpublished cited by I)enton, 1971) Hhowcd the
provision of additionid bltoyitncy hy t h r acrumulation of large amounts
of timmoniurn ions in cwtuin ocwnic crustaceans.
Vitamin A I i i ~
bccii rneasiir(vi in sonic shrimps (Fisher rt ul., 1957 ;
Fir;rhrr snd Kon. l!k%). The results in ‘l’able IX show that, except for
Bpnthcoyrti tictiin (its C:Pnnndn.u) borrdis. d l sjwcics annlysed contained
tht* vitttmin. l‘hrsc spwies tcntlrtl to bca richer in vitarnin A thttn the
t)clithic iLIi(1 littord forms so tiir tmdysed. idthoiigh the concentrution
wirs r ~ l z ~ t i v ~ l ~
lower t,hitli t litit of’ spec-irrj of’ euphausijds in which the
Itwan c~oiicr.ritratioiis of 3 I sl)ccicbs rang(’ from 0.15 pg/g wet weight in
Thyttampotin peciitrriia Ortmiinii to 18.3 pglg in Thysanoessa gregaria
Sews (IWIcbr imd Kon, 1 $15!1). ‘f’hc> rc1atk)nxhip between the vitamin
concentrution of shrini 1)s irnd t,hc taxonomic affinities is not definite,
but, scrgrstids i w l (v~rids iLI)I)(’jbr to contain larger amounts than
pen srids.
Vitamin A is not evenly distributed throughout the tissue of
euphatisiids i i i i ( l dtx(*iLi)od crirstacwns. I n tlip formclr animals tnost of
lipid in many cwpcpods iiiliubiting thv upper 325 tn, whereas the wax
esters w(!rv i he tniLin lipid constitileiit, arid triglycerides were a ininor
lipid cwniponrnt for till c.oppods esainined from depths below 625 m.
The 326-fJdh ni tlepth intcrvd t~ppeurcd to be a transition zone. A
Hitnilar tcwclcwcy was oh-rvetl by Morris (1 972) in the analysis of
lipid of ot Iicr oc(~i~tlic crustiLwirnH including a few shrimps taken from
differcwt depths in the North Atlantic and western Mediterranean.
According to him, wax chstcrs were present us only a sinall fraction
( .
:
.
20% t otcrl lipid) in t h species tnigrating in t,he upper 600-700 m
(Acnntiqhyra purpurea mid Systelluspz’s deehilis) or living on the seafloor (Ilefr~rocnvpus erhsifw A . Milnc Edwitrds and H. grimnldii A. Milne
Etlwixrils et Uoiivier). Convc~~e’ly, Acanthephyra pelayicn living below
WO n i coi1tiiid :L much higher percentage of wax esters (44-65%
total lipid).
Wax estcrs and tryglyc*critles have different densities and comprcssibilities reliLtive t o thittj of‘ seawater. According to Alexander
(2!)72) the ncritrnl huoyimvy of fish for which volurne/mass = 50
cni3kg-1 run he achieved i).\r means of wax esters if they constitute
about 20% of tho t o t d body weight. Some of the deep-living pelagic
shrimp, whose volnme/mass is near to 50 cm3kg-l, appear to have
wax esters very close to this aniount. Accumulation of wax esters by
~ n c ~ ~ p ~ l i k g i c
m d 1)ntliyycliigio shritnps is accepted as an evolutionary
aclirptation in conncxion wit ti vertical migr2Ltion and buoyancy regulation, rillied to soin(* fitctors such iLK t~hc reduction in cixrltpace calcification. l)cntjou r’f al. (unpublished cited by I)enton, 1971) Hhowcd the
provision of additionid bltoyitncy hy t h r acrumulation of large amounts
of timmoniurn ions in cwtuin ocwnic crustaceans.
Vitamin A I i i ~
bccii rneasiir(vi in sonic shrimps (Fisher rt ul., 1957 ;
Fir;rhrr snd Kon. l!k%). The results in ‘l’able IX show that, except for
Bpnthcoyrti tictiin (its C:Pnnndn.u) borrdis. d l sjwcics annlysed contained
tht* vitttmin. l‘hrsc spwies tcntlrtl to bca richer in vitarnin A thttn the
t)clithic iLIi(1 littord forms so tiir tmdysed. idthoiigh the concentrution
wirs r ~ l z ~ t i v ~ l ~
lower t,hitli t litit of’ spec-irrj of’ euphausijds in which the
Itwan c~oiicr.ritratioiis of 3 I sl)ccicbs rang(’ from 0.15 pg/g wet weight in
Thyttampotin peciitrriia Ortmiinii to 18.3 pglg in Thysanoessa gregaria
Sews (IWIcbr imd Kon, 1 $15!1). ‘f’hc> rc1atk)nxhip between the vitamin
concentrution of shrini 1)s irnd t,hc taxonomic affinities is not definite,
but, scrgrstids i w l (v~rids iLI)I)(’jbr to contain larger amounts than
pen srids.
Vitamin A is not evenly distributed throughout the tissue of
euphatisiids i i i i ( l dtx(*iLi)od crirstacwns. I n tlip formclr animals tnost of