Marine Phytal Harpacticoida from Kenya with emphasis on seagrass dwelling species. Item Type Thesis/Dissertation Authors Demeulenaere, Bruno Publisher Free University of Brussels Download date 28/09/2021 23:09:08 Link to Item http://hdl.handle.net/1834/7394 .. I FREE UNI VERSITY OF BRUSSELS FACULTY OF SCIENCES Postgraduate F.A.M.E. MA1UD PltTirAL IAI1PACTKCDRIM JmIfi IDlYA with emphasis on seagrass dwelling species <;:' Promotor: Dr. Magda VincIVincI Masters thesis presented by Bruno Demeulenaere in partial fulfilment of thethe degree of Master of Fundamental and Applied Marine EcologyEcology June 19911991 There's a theory which states that if ever anyone d;scovers exactly what the Universe is for and why ;t ;s here, it wif! instantly disappear and be replaced by something even more bizarre and inexplinexplicable.icabJe. There's another theory which states that this has already happened . .. To my parents and friends Aknowledgements firstFirst of aff, I would like to express my sincere gratitude to the promotor of this thesis, Dr. Magda Vincx. In the first place for accepting the promotorship and also for her most valuable advice. Another Person that has been a great help.throughout, is Dr. Marc Bergmans. I especiafly want to thank him for introducing me to the field of harpacticoidharpact;coid research. 1hanks7hanks to the enthousiasm of Prof. Dr. PhilipPhifip Polk, here as well as in the KMFRtKMFR.l guesthouse, this work has been a pteasurepleasure to perform. I am also very grateful!gratefull to Prof. Dr. Domien "Nikki"IINikki" Roggen (bOOks, papers, QWarenessawareness of booby traps .. .),J Dr. Frank Fiers (KBI N) for the determination of certain species and a great help in findiny literature etc ... and Dr. Rony Huys for a critical reading of the taxonomic part of the manuscript. Dr. Ezekiel Okemwa, director of the Kenyan Marine and fisheriesFisheries ResearchR.esearch Institute and his staff were all very helpfullhelpfulf and hospitable and made my stay at the institute one not to forget. Thanks. Jan, Wi/fried, Eric, Claude, franky,Franky, Peter, Pascale, Peter O. and Manuel "Ortega" in Brussels and Jane, Jan, Katrien, Joost, Pieter and Niels, Peter P'P., I Lena and many more in Mombasa : Cheerio to you all and thanks for everything. Last but certaintycertainly not least, I wish to thank my parents for giving me the opportunity to attend this postgraduate course. Contents List of figures List of tables List of terms and abbreviations Summary Introduction 1 1 Material and methods 22 Part I Diversity and Abundance .. 1 What are Harpacticoida ? 4 4 1.1 Systematic position of the Harpacticoida 44 1.2 The phytal Harpacticoida 55 1.3 Post-embryonic development 55 1.4 Sexual dimorphism 6 6 2 About seagrasses 77 3 Abundance of Harpacticoida 8 8 3.1 Abundance 88 3.2 The nematode/copepod ratio 88 4 Diversity 99 4.1 Introduction 9 9 4.2 Considerations on diversity and the indices 11 11 5 Results and discussion 1313 5.1 Seagrass samples 1313 5.2 Abundance and N/C ratio 1313 5.3 Diversity 14 14 5.3.1 The figures 1414 5.3.2 The indices 1717 5.3.2.1 Gazi 1717 5.3.2.2 English point 18 18 5.3.2.3 Margalef's index 19 19 6 TW INSPAN analysis 2323 Part II Taxonomy 1 Taxonomy 2S 1.1 Anatomy of the adult stage 25 25 1.2 Systematics 3131 1.2.1 Redescriptions 3131 1.2.2 Description of £upelte .~p. Tudor 3535 1.2.3 Some additional remarks on ... 3737 1.3 The case l!1YA 3939 2 Biogeography 40 40 References 43 43 Addendum 4747 ~---~--~~-~---......... .. .:~~u 1\ MA.i?Ii\t.~" . ~~ ~ <: t.> " 'C~:"jf !\ .' ~ r -~ , "'0' \' * '. 4.,~. '? \\ 1 ~ 'f. .~ " ''" !'oJ,'. -lJ;y....L~' \ . ...-4. \!.. ... " '! ii\S1".'TUTE ... -"..:.-.-----:-~ List of figures Fig. A:A : Map of the Kenyan southcoast Fig. B:B : Mombasa and environment Fig. C:C : Gazi Bay Part I Fig. 1 : Body shapes of the Harpacticoida Fig. 2 : Differences among diversity indices Fig. 3 : Discriminating ability of the different indices Part II Fig. a : the ancestral copepod appendage Fig. b : the harpacticoid body plan The figures under 1.1 are not numbered Fig. 1 : Tisbintra nankaurica : furcal ramus; AI; A2; Mxp Fig. 2 : Tisbintra nankaurica : PI; PS; abdomen (ventral) Fig. 3 : Ambunguipes similis : Habitus male; cephalon female; Mxp; P2, P3 and PS male Fig. 4 : Ambunguipes similis : P4; Md; Mx; Fu Fig. S:S : Ambunguipes similis : A1 male Fig. 6 : Ambunguipes similis : A1 female; A2; Pi; PS female; Genital complex and Md Fig. 7 Eupelte sp. Tudor: habitus male; A1 male; A2; Md; Mxp Fig. 8 Eupelte sp. Tudor: PI; P2; Fu; MIl; Mx; PS male and female Fig. 9 Eupelte sp. Tudor: P3; P4 Fig. 10 Dactylopusia falcifera : colour pattern cephalon, claw P3 and P3 male Fig. 11 Eudactylopus fasciatus : the spotted "SP" phenotype Fig. 12 Eudactylopus fasciatus : the striped "S" phenotype Fig. 13 Eudactylopus fasciatus : A1 male and female; A2 Fig. 14 Eudactylopus fasciatus : PS and P3 abberant sp.; abdomen (dorsal) List of tables Table 1 dry weight, surface area and their ratio for the different samples Table 2 numbers of Harpacticoida and Nematoda and their ratio Table 3 division among the three taxonomic levels considered Table 4 , of species in common between samples of the same site Table S family composition of the sites (, of total species) Table 6 diversity indices for the Gazi samples Table 7 diversity indices for the English point samples Table 8 Margalefs index of diversity Table 9 fa mily level diversity ,.., ~ ,I List of terms and abbreviations 1 1~ Al = antennule (1st antenna) 4 A2 = antenna (2nd antenna) •t Allobasis = the fused basis and first endopodite segment of the A2 of some species Basis = the third of the stem segments of biramous appendages Benp. = baseoendopodite (basendopodite, ".J.. .> Coxa =the second of the stem segments of biramous appendages Endite = accessory segments of the syncoxa of the maxilla Enp. =endopodite Exp. = exopodite Labrum =the upper lip of the mouth Md. = mandible Md.MIl. = maxillule (1st maxilla) Mx. =maxilla (2nd maxilla) Mxp. = maxilliped PI-P4 =the four thoracic locomotor appendages Pj = the fifth and last thoracic appendage. always non-locomotory and with a sexual function P6 • the first and only abdominal appendage Precoxa· the first of the stem segments of biramous appendages. Often lost or indistinguishably fused to the coxa Seta =this term is properly applied to a slender hollow projection of the cuticleenclosing an epidermal cell or part of one. Its slender shape distinguishes it from a spine and its hollow nature. recognizable articulation with the cuticle and generally larger size distinguishes it from a setule or spinule. Syncoxa = the fused precoxa and coxa of the maxilla Fu. = furcal ramus Summary In the present work. diversity and abundance of seagrass dwelling harpacticoid copepods are determined. By means of difference in diversity between the Gazi Bay and English point harpacticoid assemblages and the use of TWINSPAN analysis. the use of harpacticoids as a sensitive tool in pollution monitoring is evaluated. This is completed by a brief discussion of the usefulness of the different diversity indices. A second part comprises (re) descriptions of some species together with some remarks on interesting features of other species and an updating of geographical distribution. Marine phytal Harpac1lcolda Introduct1ion. In the framework of the Kenya-Belgium project in Marine Sciences, a preliminary study of the phytal harpacticoids of the Kenyan coast was undertaken. The aim of this work is. in first instance, to provide an introduction to the phytal harpacticoids from the region as well as to present data on abundance and diversity of this particularly interesting component of the meiofauna. The animals were obtained from seagrasses and algae but the emphasis is put on seagrass (Thalassodendron sp.) dwelling species. To evaluate the hypothesis that harpacticoids can be used as a "fine tool" in pollution monitoring, the diversity of harpacticoids from two places along the Kenyan coast will be compared among each other and also with the respective nematode/copepod ratio's (further refered to as N/C ratio) of the two sites. The N/C ratio is widely accepted as being a reflection of the condition of a system with regard to pollution stress, although it is designed to be used for sediment dwelling species. A brief discussion about the usefulness of different diversity indices,indices. by evaluation of the present results and comparison with earlier (and more extensive) studies of this kind,kind. is included in this chapter. Next to the diversity analysis, h~rpacticoid abundance will be determined. A second part of the present work is dedicated to taxonomy and biogeography. It is certainly not the objective, nor is it possible to give an account of all phytal harpacticoids. A species list is given although some species will be treated more extensively than others. Of some species.species, which have not been described accurately in the past, a redescription is presented here. The accompanying drawings form in most cases a good supplement to the already existing one's. No doubt. the drawings presented here will be .. corrected in their turn.turn. Finally, the geographical distribution of all species will be updated where necessary. , 11 Marine phytol Horpacflcoido Material and methods. The study area In order to estimate the abundance and diversity of harpacticoids on seagrasses and to evaluate their possible use as a fine tool in pollution monitoring,monitoring. samples were taken at two locations along the Kenyan coast (Fig. A) : English point (ref. "pollution") and Gazi (ref. "no pollution"). English point. the site that is considered to be under some environmental stress.stress, is situated at the mouth of Tudor Creek north of Mombasa Island.