AN ACCOUNT OF THE CRUSTACEA OF NOR WAY WITH SHORT DESCRIPTIONS AND FIGURES OF ALL THE SPECIES BY G O SARS VOL VIII COPEPODA MONSTRILLOIDA & NOTODELPHYOIDA PARTS I & II THAUMATOPSYLLID/t, MONSTRILLID/ E, NOTODELPHYIDfE (part) C WITH 16 AUTOTYPIC PLATES BERGEN PUBLISHED BYTHE BERGEN MUSEUM SOLD BY ALB CAMMERMfeYERS FORLAG CHRISTIANIA 1921 lltllll \ M INTRODUCTION the In of groups the now more has not been fully the recognised by earlier authors Giesbrecht, and Copepoda proposed by adopted by carcinologists, only the systematic rank of families these to and the NotodeLphyoida, Monstrilloida the viz., anomalous propose to give an account of I recent classification of the generally alloted is Copepoda, position of which systematic In volume present and they are both, together with several other comprised within the 2nd tribe of this suborder Podoplea, groups, heterogeneous families, which the name Ampharthraiidrla is given have otherwise shown, that the principles upon which Giesbrechts classification is founded not at all to I hold good here in cable to every case, and this in It question the may Monstrilloida; Notodelphyoida, be is that but regard to the also proved in this name the is by no Copepoda Ampharthrandria is means with the case appli- the group comprising many forms with the anterior antennae this Moreover, the genus Thaiiniatopsyllus among the conspicuously even in the principal character by which quite alike in the sexes Monstrilloida the the viz., body differs suborders mutual The many both from of, Gynuioplea relation other by Giesbrecht, distinguished between the anterior and posterior divisions of the groups here treated and known each other from the other Copepoda, have led me they ought to be raised to the rank of distinct divisions, be again subdivided into real families to are essential characters distinguishing the to the conclusion, that a and Podoplea known groups of Copepoda is of the relation of these divisions to somewhat obscure, though tendency towards the Cyclopoid type by an extreme degradation The is unmistakable whole body and its On in some instances the other hand, appendages, some forms belonging to the Notodelphyoida acquire an appearance, strongly recalling that the Lemceoida All the forms here in question are in some measure of parasitic in Crustacea habits But the parasitisme is of a very different kind in the The Monstrilloida divisions are, according to the interesting observations of Malaquin, in their juvenile state true endoparasites, living as simple, sac-like bodies in in fully some invertebrate developed natatory appendages whole are for all the blood-vessels of animals (Annelids), whereas the adult state they are freely living pelagic animals provided with power- their life The Notodelphyoida, on confined to their hosts (simple and the other hand, compound Accidians), stages of growth being mostly found together in the branchial cavity of these hosts, they Yet Tunicata but not seem, as a rule, more properly on the nourishing to feed particles introduced, together with the constantly renewed water, by the breathing process but parasites, on the juices of their and small organisms in the branchial cavity Of course they cannot at all be regarded as true as commensals or messmates Both divisions more properly here treated of are well represented in the Fauna of Norway, and as there some confusion in regard to the is exact definition of the genera and species, and moreover the descriptions and figures given by earlier authors in many cases are very incomplete and partly erroneous, think that a thorough revision of I these interesting groups, of interest accompanied by good figures, cannot fail to be MONSTRILLOIDA Remarks.- The this the most prominent of Copepoda, and antennae posterior group the total is morphological character distinguishing absence, the in adnlt state, both of of any traces of oral appendages, as also of a functional alimentary canal Of course the fully developed animal is quite in to feed the incapable ordinary manner, but may only subsist on the accumulated matter nourishing within the body-cavity parasitic existence, the adult stage being exclusively The to the its Dana, with identical they interesting number formerly were referred to a single genus, viz., Monstrilla which the genus Thanmaleiis of Kreyer was considered to all recent In into or juvenile propagation division Monstrilloida comprises as yet only a rather restricted forms, which that devoted during times, it is true, a subdivision of the all events must be comprised within the same family new genus (Thaumatopsyllus), of he- genus Monstrilla genera has been attempted, but these genera are so closely at of allied, Yet an apparently referable to the Monstril- been added by the present author, and this genus is so very different from the other Monstrilloid genera, that it cannot by any means loida, has recently be included in the same family with them, but must be regarded as the type not only of a separate family, but even of a distinct section, for which proposed the Monstrilloida name Monstrilloida cyclopimorpha appears at present cleft into cyclopimorpha and the M gennina; but each represented by a single family well I have Of course the division defined sections, of these sections is the M as yet only Section Monstrilloida cyclopimorpha The type Remarks the present author of this section another in place is the remarkable form under the name of described by Thaumatopsyllus The reception of this form within the division Monstrilloida paradoxns character: appears to be warranted by the above-mentioned general morphological the absence of both the posterior antennae and of any oral appendages total Otherwise this form differs considerably from the Monstrilloid type Fam Thaumatopsyllidae As Remarks may be this at family present only comprises a single genus, it sufficient to give the characters of that genus Gen Thaumatopsyllus, G O Generic Characters Body of adult Sars, female cyclopoid division being conspicuously dilated, the posterior slender consolidated with below short to a the 1st trunkal and blunt segment, rostral 1913 in shape, the anterior and attenuated Head and having the prominence The front produced succeeding trunk- segments normally developed, the posterior ones, however, abruptly much narrower and firmly connected with the tail, to form with it the posterior movable portion segments, the last of the body, Tail proper composed extremely slender and in narrow, rod-like female of only Caudal rami well developed, with the normal number of number limited well of and of posterior antennae defined Anterior antennae setae, and joints, extended composed No laterally appendages observable, nor of any oral of a traces distinct oral Three pairs only of natatory legs present, the posterior pairs of legs being quite rudimentary and of similar structure Two ovisacs present in female have attempted to give the most Remarks In the above diagnosis tubule i by which the present genus distinguishes itself from the The mutual relation of the chief divisions of other known Monstrilloida essential the characters, body very peculiar, and does not agree either with that mentioned by is Giesbrecht as characteristic to his suborder Gymnoplea or with that characterising the the Podoplea, movable quite a different place, viz., between the divisions occuring in the junction between the penultimate and anti- articulation at penultimate trunk-segments This this is indeed a quite unique character distinguishing genus from any other form known here be rod-like named me to the presence of only pairs shape of the last caudal segment As anomalous characters may also of natatory legs, and the narrow The genus comprises as yet only a single species, to be described below Thaumatopsyllus paradoxus, G O (Pi I haiima topsylltis paradoxiis, O O Specific Characters i.) Sars, Arch f Mathcni og Naturvidenskab No 6, p 5, w plate Female Body comparatively somewhat depressed and oblong anterior division Sars slender, oval in outline Bd XXXIII with the Cephalic seg- ment very large and narrowly rounded The succeding segments well developed, with the lateral parts closely contiPenultimate trunk-segment scarcely more than guous and rounded behind slightly contracted anteriorly, frontal part half as broad as the preceding one; last segment still smaller Tail exceedingly slender, almost attaining half the length of the body; genital segment slightly 2nd segment quite short and having the posterior edge somewhat produced dorsally; 3rd segment more than twice as long a> the other combined, and extremely narrow, rod-like, with the slightly dilated constricted in the middle; and oblong form, being about times as long as they are broad, and extremity transversely truncated quadrangular a little apical in widening setae of than the other distally; moderate seta size Caudal rami but slightly diverging of outer edge occuring about in the middle; and densely ciliated, the outermost one shorter Antennae not nearly attaining the length of the cephalic segment, and each composed of joints clothed with 3rd joint much equal-sized same the outermost joints the largest, The scattered simple setae; comparatively short and normally developed and of essential pairs of natatory legs and nearly of equal size The last pairs of legs very unlike the former, and reduced to simple small 3-articulate stems, with the middle joint very small, last rounded in shape and both with structure, rami 3-articulate Ovisacs very large, rounded oval provided with unequal apical spines in Body the in form animal highly transparent and nearly colourless, living its part being filled up with a number of clear oil-bubbles of unequal and partly of a light orange colour Eye replaced by a comparatively anterior size, transverse large of patch a light red in pigment, which, no however, trace elements could be detected of refracting female 1.65 mm of adult Length Male unknown The above-described form Remarks the other known Copepoda, both as regards structure of the several appendages history will turn Monslrillidce, and that existence within the Occurrence female sex, be out to in body a of some Trondhjem Fjord, at Selven other pelagic animals, about 60 fathoms to Christiania All from any of outward appearance and the its am much one Three specimens only ago, easily recognisable inclined to believe, that that stated this of my remarkable form, this notice Fjord, at One Drobak, of similar parasitic the all the of them was taken, other the in specimens were captured, together with by the aid of a plankton-net lowered to a depth living animal was seen moving through the water The jumping manner to that observed in most Cyclopoida however, by no means particularly agile in its movements a for the by Malaquin form leads a true its life- invertebrate animals have as yet come under the years I similar the juvenile state in many is It of in was, Section Monstrilloida genuine Remarks general section this In characters of which are comprised the typical Monstrilloida, the with coincide those given below for the sole family as yet representing the section Fam Body more General Characters anterior division posterior rather its segment more than rostral any only slightly Head and a very large length 1st Monstrillidae and elongated, with the dilated and not sharply marked of from the or less slender trunkal segment completely coalesced, forming together of a more or half the body, its less cylindrical shape, a rule occupying anterior extremity obtusely truncated, without prominence; ventral face of the segment quite and as in the greater extent of smooth, exhibiting no traces of either posterior antennae or appendages, being only provided in the median line with a small tubular process, from which a short canal leads to the inner substance of the oral any latter in female specimens retracted from the walls of the segment most peculiar manner, so as to form a rather narrow band-like chord body; the in a passing through the axis of the segment of well defined Exposed segments gradually diminishing in part of trunk size behind composed Tail poorly developed, with the number of segments more or less reduced, and exhibiting well with marked sexual strong plumose differences setae, the Caudal rami, as number of which a is rule, short, somewhat but provided variable in the different genera and ventral is of limited different some number present legs the of basal part massive, any and number, very and muscular setae powerfully rami both number of plumose up the greater part filling the within pointing in with developed, 3-articulate Last pair male much reduced, or in setae; frontal of part of the fully developed, and extending body-cavity head; the ripe ova not included the in ovisacs, but agglutinated to slender juxtaposed spines or filaments true from the ventral face of the genital issuing unequal Alimentary canal quite obliterated Ovaria, when wholly absent anteriorly ; and joint carrying a restricted very rather them being much elongated and finely ciliated, the terminal joint, exhibiting not seldom a peculiar same antennae in male distinctly hinged Natatory usual large with and composed straight forwards, female represented on each side by a single more or less lamellar in legs the in clothed Anterior antennae, unlikr of attached to others, dichotomous ramification highly refracting lenses, one '$ dark pigment a in Copepoda, extended of joints some directions, present, exhibiting imbedded lateral, generally the case in \vhat a when Eye, male replaced a by somewhat thickish, segment, these spines being in appendage, into which the clavate spermatophores are received before extrusion Of Remarks this from widely remote family localities, at only species were known, derived first Dana from the one recorded by the Sulu Sea the other by Kr0yer from thn Norwegian coast as species, though bearing very different names, These typicns are evidently nearly allied, and were also by most subsequent authors regarded as Monstrilla viridis, Thaiimaleiis as forms of of parts the the according to more In congeneric same recent remarkable oceans, and some more it times a considerable have type appeared been recorded desiderable conspicuous number to additional from different these group found diversities of species between them Thereby the first step to a subdivision of the genus Monstrilla was intimated Such a subdivision was indeed carried out in the year 1892 by Giesbrecht, who referred chiefly the the Monstrillidae characterised caudal Monstrilla, setae for the at that time known by the segmentation of the to tail nearly-allied genera, by the number and of For the one of these genera he retained the old name other he applied the name Tlianmaleus proposed by Kr0yer, am arrangement has now generally been admitted by carcinologists am by no also of opinion that these genera should be supported but and this I ; means prepared to consent with Giesbrecht haumalens to the one of these genera For recorded by Kr0yer is in it his is application I of the name quite certain, that the form not referable to Giesbrecht's genus, differing as it does, AN ACCOUNT OF THE CRUSTACEA OF NORWAY AN ACCOUNT OF THE CRUSTACEA OF NORWAY WITH SHORT DESCRIPTIONS AND FIGURES OF ALL THE SPECIES BY G SARS PROFESSOR OF ZOOLOGY AT THE UNIVERSITY OF CHRISTIANIA VOL VIII COPEPODA MONSTRILL01DA & NOTODELPHYOIDA WITH 37 AUTOTYPIC PLATES BERGEN PUBLISHED BY THE BERGEN MUSEUM SOLD BY ALB CAMMERMEYERS FORLAG, CHRISTIANIA 1921 BERGEN, A.S JOHN (1RIEGS BOKTRYKKERI OG N NILSSEN & S0N PREFACE By this Copepoda, different it Volume being group of the former group species have fully my I definitely purpose Crustacea, viz., has required no interesting species the next the less my Account Volume Ostracoda of the Norwegian upon an entirely Although my Account of to enter than Volumes, and more than 500 not by any means imagine, that it gives a am indeed convinced that the existing forms, and been described, exhaustive record of many in conclude I I still remain to be detected, especially of the smaller deep-water Harpacticoida and of the semiparasitic forms Yet, I hope that my Account may have thrown some light on this formerly much neglected part of our Fauna, and that it may serve as the basis for further investigations As to the two anomalous groups treated of in the present Volume, no record whatever has as yet been given on the Norwegian forms belonging to them I to the will not omit, also on this occasion, to tender Direction of the Bergen progress of my Museum my for the interest, most sincere thanks it still shows work G O Sars for the Copepoda Botryllophilidae Notodelphyoida P! O Sars del Pteropygus vestitus, O Sars XXXIII Copepoda Botryllophilidae G O Sars Notodelphyoida del Schizoproctus inflatus, Auriv PI XXXIV Copepoda Notodelphyoida PI } ',' I -A-? O Sars del Cryptopodus brevicauda (Canu) eruca (Norman) xxxv Copepoda Notodelphyoida Enterocolidae PI / XXXVI i V \\ -x 1, G O Sars del Enterocola bilamellata, O Sars Mychophilus roseus, Hesse Copepoda BuproridEB AnomopsyllidEB G O Sars del Buprorus Nordgaardi, G O Sars Anomopsyllus pranizoides, G O Sars PI XXXVII ... appendage (mandibles) lose of the usual pairs of limbs (anterior and posterior antennae) and soon attach themselves they study may answer It to is the posterior antenna? During the rapid growth of these... introduced, together with the constantly renewed water, by the breathing process but parasites, on the juices of their and small organisms in the branchial cavity Of course they cannot at all be... present family by the complete segmentation of the tail and the increased number of caudal more Another character by which the species of setae recognised, is from the frontal part of the head, whereas